** ****Physics**

JAMB

Questions

**655 **

Physics

- In a resonance tube experiment, a tube of fixed 5. length in closed at one end and several turning

forks of increasing frequency used to obtain

resonance at the open end. If the turning fork with

the lowest frequency which gave resonance had a

frequency ƒ1 and the next turning fork to give

resonance had a frequency ƒ2, find the ratio ƒ2/ ƒ1.

- 8 B. 3

Brick

Cord

Pull

Fig. 2

- 2 D. ½
- 1/3
- Which of the following is NOT a vectorquantity A. Force B. Altitude
- Weight D. Displacement
- Acceleration.

P1

P3 O O3

O2

P2

**Fig. 1 **

Consider the three forces acting at O and in equilibrium as shown in Fig. 1. Which of the following equation is/are CORRECT?

- P1 cos 01 = P1 cosO2
- P3 = P1 cos O1 + P2 cos O2

III. P1 sin O1 = P2 sin O2

- I only B. II only C. III only D. II and III only E. I and III only

Which of the following statements about friction it NOT correct?

- The force of kinetic friction is less than the force of static friction.
- The force of kinetic friction betweentwo surfaces is independent of the areas in

contact provided the normal reaction is

unchanged.

- The force of rolling friction between two surfaces is less than the force of sliding

friction.

- The angle of friction is the angle between the normal reaction and the force friction.
- Friction may be reduced by lubrication.

A brick at rest on a horizontal table is pulled by a horizontal cord, as shown in Fig. 2. The force of friction on the brick

- Increase if the pull increases but the brick does not move.
- Is directly horizontal to the right
- Decreases if an identical brick is placed on the first.
- Is zero if the brick is pulled hard enough tomake itslide.
- Change if the brick is turned on its side.
- The force with which an object is attracted to the earth is called its
- Acceleration B. Mass
- Gravity D. Impulse
- Weight.
- The refractive index of a liquid is 1.5. If the velocity of light in vacuum is 3.0 x 108m s-1, the velocity of light in the liquid is
- 1.5 x 103ms-1
- 2.0 x 103ms-1
- 3.0 x 103ms-1
- 4.5 x 103ms-1
- 9.0 x 103ms-1
- If the relative density of a metal is 19, what will be the mass of 20cm3 of the metal when immersed in water?
- 380g B. 400g
- 360g D. 39g
- 180g
- Which of the following statements about liquid pressure is NOT correct? The pressure
- At a point in a liquid is proportional to the depth.
- At any point in a liquid isthe same at the same level.
- Is exerted equally in all directionsat any point.
- Of a liquid at any point on the wall of its

**656 **

container acts in a direction

perpendicular to thewall.

- At a particular depth depends on the shape of the vessel.
- A ship traveling towards a cliff receives the echo of its whistle after 3.5 seconds. A short while later, it receives the echo after 2.5 seconds. If the speed of sound in air under the prevailing conditions is 250m s-1, how much closer is the ship to the cliff?
- 10 m B. 125 m
- 175 m D. 350 m
- 1,000 m
- Which of the following is NOT correct? I. The pitch of a sound note depends on the frequency of vibrations.
- The intensity of a sound note is proportional to the amplitude of

vibrations.

III. Beats are produces by two sources of sound because one wave is travelling

faster than the other.

- When two sources of sound of frequencies 500 Hz and 502 Hz are

sounded together, a neat frequency of 2

Hz is observed.

- The first harmonic of a note has double the frequency of the fundamental note.
- If the pressure on 1000cm3 of an ideal gas is doubled while its Kelvin temperature is halved, then the new volume of the gas will become
- 25 cm3 B. 50 cm3
- 100 cm3 D. 200 cm3
- 400 cm3
- A train has an initial velocity of 44m/s and an acceleration of –4m/s2. Its velocity after 10 seconds is
- 2m/s B. 4m/s
- 8m/s D. 12m/s
- 16m/s.
- Which of the following conditions are necessary and sufficient for total internal reflection to take place at the boundary between two optical media? I Light is passing from optically denser medium to optically less dense medium.

II Light is passing from optically less dense medium to optically denser medium.

III Angle of incidence is greater.

IV Angle of incidence iflesser.

- I and IIonly
- II and II only
- III and IV only
- I and IIIonly

- C.

I and II I and II

- D.

II and III III and IV

- II and Iv only

- IV and V.
- Which of the following statements about defects ofvision is/ areCORRECT
- For a long sighted person, close objects appear blurred.
- For a sort sighted person, distant objects appear blurred.

III. Short sight is corrected by using a pair of converging lenses.

- I onl B. II only
- I and II onl
- II and IIIonly
- I, II andIII.
- The range of wavelengths of the visible spectrum is 400nm – 700nm. The wavelength of gamma rays is
- Longer than 700nm
- Shorter than 700nm but longer than 400nm
- 550nm
- Shorter than 400nm
- Infinite
- A man of mass 50kg ascends a flight of stairs 5m high in 5 seconds. If acceleration due to gravity is 10m s-2, the power expendedis
- 100W B. 300W
- 250W D. 400W
- 500W
- Which of the following arrangements in the sequence shown can be used to obtain a pure spectrum of whitelight?
- Source, slit, converging lens, prism, converging lens, screen.
- Source, slit, diverging lens, screen.
- Source, converging lens, prism, diverging lens, screen.
- Source,slit, prism, diverging lens, screen 19. 10V

*I*12Ù

*I*2

**657 **

2Ù *I*3

*I*42Ù

*I*51Ù Fig. 3.

20V 1Ù

20V

currents in each resistor is

- 1 A B. 4 A
- 16A D. 18A
- 36A
- In the circuit shown in Fig. 4, T is a resistor whose resistance falls astemperature increases. L1and L2 are lamps. Assuming the cell has negligible internal resistance, as the temperature of T increases
- L1 becomes brighter, L2 becomes dimmer. B. L1 and L2 becomes brighter.
- L1 becomes dimmer, L2 becomesbrighter. D. L1 becomes brighter, L2 does not change. E. L becomes dimmer, L does not change.

The diagrams in Fig.3 show three circuits. The

2 1

internal resistances of the batteriesare negligible. 1L

Which of the currents is the largest? T

T

*I**1*B.*I**2**I**3*D.*I**4**I**5*- A milliameter with full scale deflection of 100mA

has an internal resistance of 5 ohms. It would be

converted to an ammeter with a full scale deflection

of 1A by connecting a resistance of

L2

- 5

/

ohm in series with it

Fig. 4.

/

99

ohm in parallel with it 25. Which of the diagrams in Fig. 5 gives the correct

- 599
- 99/ ohm in parallel withit

5

- 99/ ohm in series with it

5

- 2 ohmsin series with it
- It is usual to transmit electric power at high voltage and low current. Which of the following are possible advantages of the method.

I Heat losses are reduced because the currents are small.

II Thin wires can be used because small currents are flowing.

III The power can flow faster because the voltage is high.

- I only
- I and IIonly
- II and IIIonly
- I and IIIonly
- I, II andIII.

resultant R of two vectors P and

Q?

P P

R

I II

R

Q

Q

P P

R

III IV

R

- The linear expansivity if brass is 2 x 10-1 0C-1. Ifthe P volume of a piece of brass is 100cm3at 00C, what

will be its volume at 1000C?

R fig 5.

- 10.02 cm3 B. 10.04 cm3 V Q C. 10.06 cm3 D. 10.20 cm3
- 102.00cm3
- A 24V potential difference is applied across a

parallel combination of four 6-ohm resistors. The

**658 **

- I B. II
- III D. IV
- V
- The electrochemical equivalent of a metal is 0.126 x 10-6 kg/C. The mass of the metal that a current of 5A deposit from a suitable bath in 1 houris
- 0.0378 x10-3kg
- 0.227 x 10-3kg
- 0.378 x 10-3kg
- 0.595 x 10-3kg
- 2.268 x 10-3kg
- Ripples on water aresimilar to light waves in that they both
- Have the samewavelength
- Are longitudinal
- Cannot be reflected
- Travel at the same speed
- Can be refracted and diffracted.
- A piece of wood is floating on water. The forces acting on the wood are
- Upthrust and reaction.
- Weight and reaction
- Weight and upthrust
- Upthrsut and viscosity
- Weight and viscosity.
- Of the following derived units, the one that is not a unit of power is

end. Calculate the unstretched length of the spring assuming Hooke’s law is obeyed.

- 9.33 cmB. 10.00cm
- 10.66cm D. 12.00cm
- 15.00cm
- Each of the diagrams in Fig. 6 represents two current carrying conductors situated close to each other. In which two diagrams are the forces between the two wires attractive?

I

II

III

- Joule/second IV B. Ampere/volt
- Amphere2volt
- Ohm2/volt
- Volts2/ohm.
- A force of 16N applied to a 4.0kg block that is at rest on a smooth horizontal surface. What isthe

velocity of the block at *t *= 5 seconds? V A. 4 m/s B. 10 m/s

- 20 m/s D. 50 m/s
- 80 m/s
- 1,000 identical drops of oil of density 5000kg/m3 have a total mass of 5 x 10-4kg. One of the drops

Fig .6

forms a thin film of area 0.5m2 on water. The thickness ofthe film is

- 2x 10-8m B. 2 x 10-9m
- 2x 10-7m D. 3x 10-9m
- I andV C. II and IVD. E. III andIV
- I and III II andV

- 2.8x 10-8m.
- The total length of a spring when a mass of 200g is hung from its end is 14cm, while its total length is 16cm when a mass of 30kg is hung from the same
- Which of the following statementsis CORRECT? I The mass number is equal to the total number of protrons and electrons in an

atom.

II The atomic number is equal to the number of protrons in an atom

**659 **

III The number of electrons in an atom is equal to the total number of protons and

neutrons in the nucleus.

- I only B. II only
- III only D. I and II only E. II and III only.
- A short response time is obtained in a liquid-in glass thermometer when the
- Bulb islarge and thick-walled.
- Stem islong and thin.
- Bulb issmall and thick-walled.
- Bulb is high densityand the bore islarge. E. Bulb isthin-walled and the liquid is a good conductor of heat.
- A machine has a velocity ratio of 5. It requires a 50kg weight to overcome a 200kg weight. The efficiency is

P

R

Fig. 7

In Fig. 7 above, QR is a vertical conductor and the current I flows from R to Q. P is a point on the horizontal plane and it to the South of the wire. The direction of the magnetic filed at P due to the current is

- 4% B. 5% A. Upward B. North C. 40% D. 50% C. South D. West E. 80% E. East

- If the normal atmospheric pressure in a laboratory supports a column of mercury 0.76m high and the relative density of mercury is 13.8, then the height of water column which atmospheric pressure will support in the same laboratory at the same time is
- 0m B. 10m
- 13m
- 14m
- 18m
- An electric current of3A flowing through an electric heating element of resistance 20 embedded in 1,000g of an oil raisesthe temperature ofthe oil by 100C in 10 seconds, then the specific heat capacity of the oil is
- 1.8 J/g B. 0.6 J/g
- 0.18 J/g 0C D. 1.8 J/g 0C E. 0.06 J/g0C
- The difference of potential between the terminals of a cell is 2.2 volts. When a 4 ohm resistor is connected across the terminals of this cell, the potential difference is 2 volts. What is the internal resistance of the cell?
- 0.10 ohms B. 0.25 ohms C. 0.40 ohms D. 2.50 ohms E. 4.00 ohms.
- Q

*I *

- Which of the following best describes the energy changes which take place when a steam engine drives a generator which lights a lamp?
- Heat Light Sound Kinetic
- Kinetic Light Heat Electricity
- Heat Kinetic Electricity Heat and Light
- Electricity Kinetic Heat Light
- Heat Sound Kinetic Electricity.
- Which of the following statements clearly describe the behaviour of the fire alarm shown in Fig. 8 below given that the linear expansivities of copper and steel are 2.0 x 10-5/0C and 1.2 x 10-5/0C respectively?

Electric

bell

Copper

P Steel Q

Fig. 8.

**660 **

I The bimetallic strip will not be able to close the circuit when there isfire

II The bimetallic strip will close thecircuit when there isfire

III If the copper and steel are interchanged, the circuit will close when there isfire.

- I only B. II only
- III only D. I and III
- II andIII
- Four equal resistors R1, R2, R3 and R4 are connected in series asshown in Fig 9 below. V1, V2and V3are voltmeters connected as indicated. Which of the following relationsis
**CORRECT?** - V1 = V3 = V2 .2
- V1 = 2V2 =V3 C. V = ½ V = V2

1 3

- V1 – V3 =V2
- V2 – V1 = V3 .2
- Which of the following may be used todetermine relative humidityin a physics laboratory?

I Manometer

II Wet-and-dry bulb hygrometer

III Hair hygrometer

IV A hydrometer

- I only
- II and IIIonly
- II only
- III only
- II, III and IV only
- PQ is a thin rod on a horizontal table, RS is a plane mirror inclined at 450C to the horizontal as shown in Fig. 10 above. The image of PQ as seen in the mirror by the eye, Tis
- Horizontal
- Parallel to the mirror
- At infinity
- Vertical
- Highlymagnified.
- The speed oflight in vacuum is 3.0 x 108m s-1. Ifthe refractive index of a transparent liquid is 4/3 then the speed of light in the liquid is
- 0.44 x 108ms-1
- 2.25 x 108ms-1
- 3.0 x 108ms-1
- 4.0 x 108ms-1
- 4.33 x 108ms-1
- Ifthe force on a charge of 0.2 coulomb in an electric field is 4N, then the electric field intensity of the field is
- 0.8 B. 0.8 N/C C. 20.0N/C D. 4.2 N/C
- 20.0C/N
- The specific latent heat of vapourization of a substance is always
- Lessthan itsspecific latent heat offusion. B. Greater than its specific heat offusion. C. Equal to its specific latent heat offusion D. All of the above depending on thenature of the substance
- None of the above
- Longitudinal waves do notexhibit
- Refraction B. Reflection C. Diffraction D. Polarization E. Rarefaction

Fig. 11 above shows an inverted U-tube with the open end, O of one limb below the level, W, of the water in a tank. In order that water should begin to flow from the tank it is necessary that

- The U-tube is completelyfilled with water and P should be higher than W.
- P should be lower than O and W
- P should be lower than W and O should reach to the bottom of the vessel.
- The U-tube is completelyfilled with water and P should be lower than W.
- The U-tube is completely filled with water and O should reach the bottom of the

vessel.

**661 **

Physics 1984

- The distance travelled by a particle starting from rest is plotted against the square of the time elapsed from the commencement of motion. The resulting graph is linear. The slope ofthis graph is a measure of
- Initial displacement
- Initial velocity
- Acceleration
- Half the acceleration
- Half the initialvelocity

P T

Q R S

0.1N 0.4N

Fig. 1

In Fig. 1, PT is a uniform metre rule pivoted at R, the 70cm mark. Two forces 0.1N and 0.4N are applied at Q, the 60cm mark and S. the 85cm mark. Ifthe metre rule is kept in equilibrium by the forces and its weight, then the weight ofthe metre rule is

- 0.25 N B. 0.30 N
- 0.35 N D. 0.50 N
- 0.56 N
- For which of the underlisted quantities is the derived unit
*ML**2**T**-2*correct?

I Moment of a force

II Work

III Acceleration

- I only B. II only
- III only D. I and II
- II andIII
- What volume of alcohol with a density of 8.4 x 102kg m-3 will have the same mass as 4.2m3 of petrol whose density is 7.2 x 102kg m-3?
- 1.4 m3 B. 3.6 m3
- 4.9 m3 D. 5.0 m3
- 5.8 m3
- For correcting long sight defectsin the human eye we require a
- Converging lens
- Diverging lens
- Microscope
- Periscope
- Plain glass sheet.
- For a concave mirror to form a real diminished image, the object must be placed
- Behind themirror
- Between the mirror and infocus
- Between the focus and the center of curvature
- At the center of curvature
- At a distance greater than the radius of curvature.
- The unit quantity of electricity is called A. The ampere
- The volt
- The coulomb
- The ammeter
- Electromotive force.
- The resistance of a wire depends on A. The length of thewire
- The diameter of the wire
- The temperature of the wire
- The resistivity of thewire
- All of the above.
- What is the resistance ofthe circuit shown in Fig. 2.

2Ohms

2Ohms

3 Ohms

4Ohms

Fig. 2

- 4 Ohms B. 11 Ohms C. 19/ Ohms D. 17/ Ohms 5 4
- 8Ohms
- Two cells, each of e.m.f. 1.5V and an internal resistance 2Ohms are connected in parallel. Calculate the current flowing when the cells are connected to a 1 Ohmsresistor.
- 0.75 Ohms B. 1.5 Ohms C. 0.5 Ohms D. 1.0 Ohms E. 0.6 Ohms
- Which of the following components is NOT contained in a dry cell?A

**662 **

- Carbon rod
- Paste of magnesiumdioxide
- Paste of ammoniumchloride
- Zinc case
- Copper rod.
- Which of the following can be described as high tension transmission?
- High resistance and low voltage
- Low current and high voltage
- High current and low voltage
- High voltage and zero current
- High current and lowresistance.
- All the heat generated in a 5 ohms resistor by 2A flowing for 30 seconds is used to evaporate 5g of liquid at its boiling point. Which of the following is the correct value of the specific latent heat of the liquid?
- 120 J B. 60 J g-1 C. 120 J g-1 D. 1 500 J
- 1 500 Jg-1
- When vibration occurs in an air column, the distance between a node and an antinodes is equal to
- One-quarter of the wavelength
- One-half of the wavelength
- The wavelength
- Twice the wavelength
- Four-times the wavelength.
*NOT*correct?

I Pressure changes do not affect the speed of sound in air

II The velocity of sound increases with temperature

III The quantity of a note depends only on its frequency.

- I only B. II only
- III only D. I and IIIonly
- II and IIIonly.
- Of two identical turning forks with natural frequency 256 Hz, one isloaded so that 4 beats per second are heard when they are sounded together. What is the frequency of the loaded turning fork?
- 260Hz B. 252Hz
- 248Hz D. 264Hz
- 258Hz
- Dew point is the temperature at which water vapour in the atmosphere
- Has a relative of fifty percent.
- The lower and upper fixed points marked on a mercury-in-glass thermometer are 210mm apart. The end ofthe mercury column in the tube is 49mm above the lower fixed point in a room. What is the temperature of the room in degreesCelsius?
- 55.30C B. 23.3 0C
- 49.00C D. 16.1 0C
- 76.70C
- If a solid changes directly into a gas when heat is applied the process is called
- Vaporization
- Evaporation
- Sublimation
- Ionization
- Conversion.
- A plane inclined at an angle of 300to the horizontal has an efficiency of 60%. The force parallel to the plane required to push a load of 120N uniformly up the plane is
- 60 N B. 100N
- 120N D. 200N
- 240N
- A body of mass 5kg initially at rest is acted upon by two mutually perpendicular forces 12N and 5N as shown in Fig. 3. If the particle moves in the direction QA, calculate the magnitude of the acceleration.
- 0.40ms-2B. 1.40m s-2
- 0.26ms-2 D. 2.60m s-2
- 3.40ms-2

A

12N

è

O

5N

Fig. 3

20

10

Force

- Turns into steam
- Solidifies into icepellets C. First condenses into liquid form D. Is just sufficient to cause cooling

(N)

0 5 1 0 15 20 Fig. 4 Distance (m)

**663 **

body by the force during the first 10 metres of motion is

- 100J B. 150J
- 200J D. 300J
- 600J
- A simple pendulum, 0.6m long, has a period of 1.5 s. what is the period of a similar pendulum 0.4m long in the same location?
- 1.4 2/ s B. 1.5 3/

3 2

- 2.25 s D. 1.00 s
- 2.00 s

A force varying linearly with the distance acts on a body as shown in Fig. 4. The work done on the body by the force during the first 10 metres of motion is

- 100J B. 150J
- 200J D. 300J
- 600J
- A simple pendulum, 0.6m long, has a period of 1.5 s. what is the period of a similar pendulum 0.4m long in the same location?
- A particle moves in a circular orbit ofradius 0.02m. If the speed of the particle is 0.88m s-1, calculate its frequency in cycles per second.
- 2.0 B. 7.0
- 8.8 D. 14.0
- 17.6
- Heat is supplied uniformly at the rate of 100W to 1.0 x 10-2kg of a liquid for 20 seconds. If the

temperature of the liquid rises by 50C, then the specific heat capacity of the liquid is

- 2.0 x 102J kg-1 K-1
- 2.0 x 102J kg-1
- 4.0 x 104J kg-1 K-1
- 4.0 x 104J kg-1
- 8.4 x 103J kg-1 K-1
- A given mass of an ideal gas occupies a volume V at a temperature T and under a pressure P. If the pressure is increase to 2P and the temperature reduced to 1/2T, then the percentage change in the volume of the gasis
- 0 % B. 25 %

- 1.4 “ 2/ s B. 1.5 “3/ C. 75 % D. 300 % 3 2
- 2.25 s D. 1.00 s E. 400 %

- A small steel needle is carefully floated on water in a beaker. When a few drops of kerosene are introduced into the water the needle sinks. Which of the following statements correctly explain(s) the observation?

I There is a tension on the water surface. II Kerosene reduces the density of water so that the needle becomes denser than

water.

III Kerosene reduces the surface tension of water.

- I only B. II only
- III only D. I and II
- I and III
- Which of the following statements describes an atom accurately?

I Atoms of all elements are identical

II An atom contains a nucleus and number of electrons.

III Due to the electronsin the atom, an atom is negatively charged.

IV Electronsin the atom move in circular orbits round the nucleus.

- I and II B. II and III C. III and IV D. II and IV E. I, II and III
- Which of the following properties of matter
*CANNOT*be utilized for temperature measurement? The - Length of a liquidcolumn
- Volume of a gas at constant pressure. C. Pressure of a gas at constant volume D. Resistance of a metallic wire
- Current produced in a photoelectric effect.
- The image and object distances of a converging mirror are related by the equation 1/ = 1/ + 1/ and ƒ v u the magnification of the image is m = v/u. Which of the graphs below represents the relation between m and v?
- D.

*m m *

*v v *

**664 **

B C. Increasing the speed ofrotation. *m m *D. Making the field magnet longer. E. Using low resistance copper coil.

*v v *

II

C..

*m *

- I S

N

*v** *

- Which of the following statements about the compound microscope and astronomical telescope

is (are) correct?

I The final image of a compound

microscope is located atinfinity.

III

Earth’s magnetic field

Fig. 5

II The final image of the astronomical

telescope is always erect.

III The objective lens of a compound

microscope has a very short focal length.

- I only B. II only
- III only D. I and III
- II andIII
- A coin is placed at the bottom of a cube of glass
*t*cm thick. If the refraction index of the glass is ø, how high does the coin appear to be raised to an observer looking perpendicularly into the glass? A. 1 .

t – ø

Ashort bar magnet is placed in the earth’s magnetic field as shown in Fig. 5. Which ofthe points II and II is (are) possible position(s) of a natural point? A. I only B. II only C. III only D. I and II E. I, II andIII

4 UF

3 UF

- t(ø – 1)

ø

- t>ý 1 + 1/ø?ý
- t .

ø

- t
- The electromotive force obtained from a simple dynamo may be increased by
- Increasing the cross-sectional area of the coil.
- Winding the coil on a soft-iron armature so as to increase the magnetic flux

through the coil.

4 UF 2 UF

Fig. 6

In the circuit in Fig. 6, calculate the effective capacitance between X and Y.

- ¾ UF
- 2 10/ UF

13

- 12 UF
- 4 12/ UF

13

- 13 UF
- Agun ofmass 2.0kg fires a bullet ofmass 1.6 x 10-2kg due East. If the bullet leaves the nozzle of the gun

**665 **

with a velocity of 150m s-1, what is the recoil velocity of the gun?

- 150 m s-1 dueWest
- 1.2 x 10-4 m s-1 due West.
- 1.2 m s-1 due West
- 1.2 m s-1 dueEast
- 150 m s-1 dueEast
- Normal atmospheric pressure at sea-level is 105N m-2and the acceleration due to gravity is approximately 10m s-1. If the atmosphere has a uniform density of 1kg m-3, its height is
- 100 m
- 1000 m
- 10 000m
- 100 000m
- 1000 000m
- Which of the following is a correct explanation of the inertia of a body?
- Ability to overcome the earth’sgravity B. Reluctance to stop moving
- Readiness to start moving
- Reluctance to start moving and its readiness to stop moving once it has

begun to move

- Reluctance to start moving and its reluctance to stop moving once it has

begun to move.

- If a water pump at Kainji Dam is capable oflifting 1000kg of water through a vertical height of 10m in 10s, the power of the pump is
- 1.0 kW B. 10.0 kW
- 12.5kW D. 15.0 kW
- 20.0kW

(g = 10m s-2)

- What isthe apparent colour of a RED SHIRT when viewed in PURE green light?
- Red B. Green
- Yellow D. Black
- Blue
- The spectrum of white light consists of coloured lights arranged in the following order
- Blue, red, green. Yellow, indigo, violet, orange.
- Red, orange, yellow, green, blue, indigo, violet.
- Red, orange, yellow, indigo, green, blue, violet.
- Indigo, green, blue, violet, yellow, red, orange.
- Yellow, blue, green, violet, orange,indigo, red.
- Cathode rays are
- High-energy electromagneticwaves B. Protons
- Streams of electrons
- Neutrons
- Radio waves
- A device that convertssound energy into electrical energy is
- The horn of a motor car
- An A.C.generator
- A microphone
- The telephone earpiece
- Aloudspeaker.
- Which of the following

I â-particles

II Protons

III Neutrons

IV á-particles

may be found in light nuclei?

- I andII
- I and III
- II and IV
- II and III
- I, II, andIII.
- Radio waves have a velocity of 3 x 108m s-1. Aradio station sends out a broadcast on a frequency of 800 kHz. The wavelength of the broadcastis
- 375.0m
- 267.0m
- 240.0m
- 37.5m
- 26.7m

X

4Ohms

Y

6Ohms

Fig. 7

In the diagram above (Fig. 7), X and Y are resistances 45 ohms and 65 ohms respectively. If power dissipation in X is 10W, then power dissipation in Y is

- 2.4 W B. 4.0 W
- 6.0 W D. 6.7 W
- 15.0W

**666 **

- What is the cost of running five 50W lamps and four 100W lamps for 10 hours if electrical energy costs 2 kobo per kWh?
- N 0.65 B. N 0.13 C. N 3.90 D. N 39.00 E N 234.00
- Which of the following statements is (are)
*NOT*true about the emission of photoelectrons from metallic surfaces?

I All metallic surfaces emit the same number of photoelectrons in a givenlight.

II Most metallic surfaces in visible and infrared light.

III A metallic surface emits photoelectric only iffrequency of the incident light is higher

than its own characteristic threshold

frequency.

- I only B. II only
- I and II D. II andIII E. III only
- A galvanometer of resistance 5.0Ù has full-scale deflection for a current of 100mA. Howwould its range be extended to 1.0A by placing a resistance of
- 5/ Ohms in parallel
- Fig 8 above represents an insulated cylindrical coil or copper wire wound round a paper tube. The

ends of the coil are connected to a sensitive galvanometer. When a magnet was plunged into the coil it was observed that the galvanometer needle gave a deflection. Which of the following correctly describes this experiment?

- The effect illustrated is induced electromotive force.
- The strength of the current produced is inversely proportional to the speed with

which the magnet is plunged into the coil.

- The direction of the current is always such as to enhance the change producing
- The galvanometer gave a permanent

/

9

- 95 Ohms in series deflection.

- 45 Ohms in parallel D. 45 Ohms inseries E. 9/ Ohms in parallel. 5
- On removing the magnet from the coil the

galvanometer deflected in the same

direction.

Physics 1985

- Which of the following is
*NOT*a fundamental S.I. unit? - Metre B. Ampere
- Kelvin D. Second
- Radian
- A simple pendulum with a period of 2.0s has its length doubled. Its new period is
- 1.00 s B. 1.41s
- 0.35 s D. 2.83s
- 4.00 s
- Which of the following statements are true about the spring balance and the chemicalbalance?

I Both are used to measure the mass of an object.

II Either of them may be used to measure the weight of an object.

III The spring balance works on the principle of Hooke’slawwhile the chemical balance works on the principle of moments.

IV A change in gravity changes the readings of a spring balance but not that of a chemical balance.

- I and IV B. II andIII C. III and IV D. I, II, and III E. I and III.

**667 **

- Which of the following types of motion are oscillatory?

I A driving board when used by adriver. II Themotion ofthe balance wheel of a wrist watch.

III The motion of the turn-table of a record player.

IV The motion of the center of a ten kobo piece as it rolls down an inclinedplane.

- The motion of the needle of a D.C. ammeter into which a lowA.C. current is

passed.

- I and II only B. I, II andIII C. II, IIIand IV D. I, II andV E. III,IV, andV.
- A metal block of mass 5kg lies on a rough horizontal platform. If a horizontal force of 8N applied to the block through its centre of mass just slides the block on the platform, then the coefficient of limiting friction between the block and the platform is
- 0.16 B. 0.63
- 0.80 D. 1.60
- 2.00
- Which of the following is
*NOT*a force? - Friction
- Tension
- Upthrust
- Weight

10

8

- Impulse.
- Two masses 40g and 60g respectively, are attached firmly to the ends of a light metre rule. The centre of gravity of the system is

Velocity

(ms-1) 6

4

2

0 1 2 3

Time (s)

4 5 6

Fig 1

- At the mid-point ofthe metre rule B. 40cmfrom the lighter mass
- 40cm from the heavier mass
- 60cm from the heavier mass
- indeterminate because the metre-rule is light.

P

The graph Fig. 1 above describes the motion of a particle. The acceleration of the particle during the motion is

- 0.00m s2 B. 0.25m s-2 C. 4.00m s 2 D. 8.00m s-2

10 20 300 80

- 10.00m s-2 N

M

L R O

- If a car starts from rest and moves with a uniform

acceleration of 10m s-2for ten seconds, thedistance it covers in the last one second of the motion is A. 95 m B. 100m

30kg

Fig 2

- 500m D. 905m
- 1000m
- A block of mass 2.0kg resting on a smooth horizontal plane is acted upon simultaneously by two-forces, 10N due North and 10N due East. The magnitude of the acceleration produced by the forces on the block is
- 0.10m s-2 B. 7.05m s-2
- 10.00m s-2 D. 14.10m s-2
- 20.00ms-2

In Fig. 2 above. MN is a light uniform metre rule pivoted at O, the 80cm mark. A load of mass 3.0kg issuspended on the rule at L, the 10cm mark. Ifthe rule is kept in equilibrium by a string RP, fixed at P and attached to the rule at R, the 20cm mark, then the tension T in the string is

- 25 N B. 50 N C. 250 N D. 5 000N E. 25000N

A 0.05kg bullet traveling at 500m s-1 horizontal strikes a thick vertical wall.Aload ofmass 3.0kg is

**668 **

suspended on the rule at L, the 10cm mark. If the rule is kept in equilibrium by a string RP, fixed at P and attached to the rule at R, the 20cm mark, then tension T in the string is

- 25 N B. 50 N C. 250 N D. 5 000N E. 25000N
- A force of 100N stretches an elastic string to a total length of 20cm. If an additional force of 100N stretches the string 5cm further, find the natural length of the string.
- 15cm B. 12cm
- 10cm D. 8 cm
- 5 cm
- Two drivers G and H are at depths 20m and 40m respectivelybelowthe water surface in a lake. The pressure on G is P1 while the pressure on H is P1. If the atmospheric pressure is equivalent to 10m of water, then the value of P2/P1is
- 0.50 B. 0.60
- 1.67 D. 2.00
- 3.00
- The areas of the effort and load pistons of a hydraulic press are 0.5m2and 5m2respectively. If a force F1of 100N is applied on the effort piston, the force F2 on the load is
- 10 N B. 100 N
- 500 N D. 1000 N
- 5 000N
- A metal cube of volume 103mm3is lowered into a measuring cylinder containing water. If the internal cross-sectional area of the cylinder is 1.5 x 102 mm2, by how much does the water level rise in the

cylinder?

- Two liquids, P at a temperature of 200C and Q at a temperature of 800C have specific heat capacities of 1.0J kg-1 0C-1and 1.5J kg-1 0C-1respectively. If equal masses of P and Q are mixed in a lagged calorimeter, then the equilibrium temperature is A. 440C B. 500C
- 560C D. 600C
- 700C
- A quantity of gas occupies a certain volume when the temperature is – 730C and the pressure is 1
**.**5 atmospheres. If the pressure is increased to 4**.**5 atmospheres and the volume is halved at the same time, what will be the new temperature of the gas? A. 5730C B. 3270C - 3000C D. 1100C
- 270C
- In a gas experiment, the pressure of the gas is plotted against the reciprocal of the volume of the gas at a constant temperature. The unit ofthe slope of the resulting curve is
- Force B. Force/m
- Work D. Force/m3 E. Energy/m2.
- Water shows anomalous behaviour
- Below00C
- Between 00C and40C
- At exactly40C
- Between 40C and1000C
- Above 1000C
- Two thermos flasks of volume
*Vx*and*Vy*are filled with liquid water at an initial temperature of 00C. After some time the temperatures were found to be*èx, èy*respectively . given that

- 6.67 x100mm B. 8.50 x 102mm
*Vx*= 2 and*èx*= ½

- 1.15 x103mm D. 2.50 x 103mm E. 1.50×105mm

*Vy èy *

The ratio of the heat flow into the flasks is

- A uniform cylindrical block ofwood floatsin water A. 1/ B. ½

with one-third of its height above the waterlevel. In a liquid ofrelative density 0.8, What fraction of its height will be above the liquid level?

4

- 4 D. 1 E. 2

- 1/ C. 1/ E. 5/

6 3 6

- 1/ D. 4/
- A good calorimeter should be of

5

- Low specific heat capacity and low heat

5

conductivity.

- Lowspecific heat capacity and high heat

- A thin aluminum plate has a surface area of1,500m2 at 200C. What will be its surface area when it is cooled to – 200C?

(Take the linear expansivityof aluminium to be 2.5 x 10-5K-1)

- 1.503m2 B. 1.500 m2 C. 1.498m2 D. 1.497 m2 E. 1.490m2

conductivity.

- High specific heat capacity and lowheat conductivity
- High specific heat capacity and lowheat conductivity,
- Dull surface and low heat conductivity.

**669 **

- Which ofthe following statementsis
*NOT*correct? - Boiling occurs when the saturated vapour pressure of the liquid involved

equals the externalpressure.

- Both the boiling point and the saturated vapour pressure of a given liquiddepend

on the external pressure.

- The saturated vapour pressure rises with increase in temperature.
- The saturated vapour pressure is independent of the volume available for

the vapour.

- It is possible to boil water at a lower temperature than 1000C at highaltitude.
- Which of the following phenomena
*CANNOT*be explained by the molecular theory of matter? - Expansion B. Conduction C. Convection D. Radiation E. Evaporation.
- In order to find the depth of the sea. A ship sends out a sound wave and receives an echo after one second. If the velocity ofsound in water is 1500m/s, what is the depth of the sea?
- 0.75km B. 1.50km
- 2.20km D. 3.00km
- 3.75km
- When a sound wave passes from air into water its A. Speed and frequency increase but its wavelength remains the same.
- Speed and wavelength increase but its frequency remains thesame
- Speed decreases.
- Speed remains the same but its frequency and wavelength change.
- Speed increases but its frequency and wavelength decrease.
- Ifthe fundamental frequencyof a closed pipe organ on a day when the speed of sound is 340m s-1is 170 Hz, then the length ofthe pipe is
- 50cm B. 70cm
- 100cm D. 150cm
- 200cm
- An object is placed 15cm in front of a concave mirror ofradius 40cm. The image formed is
- Virtual and 60cm behind the mirror
- Real and 60cmin front ofthe mirror
- Virtual and atinfinity
- Real and at infinity
- Virtual and 40cmfromthemirror.
- A 450triangular glass prism can be used as a reflector of light because
- Refraction never takes place in such a prism
- The angle of reflection equals the angle of incidence.
- The refractive index of glass is less than 1
- It is transparent
- The critical angle for glass is less than 450
- A convexmirror is used as a driving mirror because I Its image iserect

II It has a large field of view

III It has a long focal length

Identify the *CORRECT *statement(s).

- I and IIIonly
- I and IIonly
- II and IIIonly
- I, II and III only
- I only
- Two rays of light from a point below the surface of water are equally inclined to the vertical and are inclined to each other at 600in water. What is the angle between the rays when they emerge into air?

(Take the refractive index of water to be 4/3)

- 41.80 B. 44.10
- 60.00 D. 83.60
- 120.0.
- A narrow beam of white light can be split up into different colours by a glass prism. The correct explanation isthat
- White light is an electromagnetic wave
- The prism has all the colours ofthe white light C. White light has undergone total internal reflection in the prism
- Different colours of white light travel with different speeds in glass.
- White light consists of yellow, green and red colours.
- A charge of one coulomb liberates 0.0033g of copper in an electrolytic process. How long will it take a current of 2A to liberate1.98g of copper in such a process.
- 5 minutes B. 30 minutes C. 50 minutes D. 60 minutes E. 120 minutes
- If the distance between two stationary charged particles is doubled, the magnitude of the electrostatic force between them will be

**670 **

- Passing on an electric current through a solenoid.
- Repeated stroking of the specimen with a magnet
- Repeated stroking of the specimen in opposite directions with two magnets
- Heating of the specimen
- Hammering of the specimen in the earth’s magnetic field’s
- Which ofthe following will convert a milliammeter to a voltmeter?
- Low series resistance
- Low parallelresistance
- High series resistance
- High parallel resistance
- Parallel resistance equal to milliameter resistance.
- Which of the graphs A – E (Fig. 3) representsthe current-voltage (I – V) relationship for a cell with internal resistance?
- An electric kettle, connected to a 240V mains, produces 6.0 x 105J of heat energy to boil a quantity of water in 5 minutes. Find the resistance of the kettle.
- 14.4 ohms B. 28.8 ohms C. 144 ohms D. 288 ohms E. 2 880 ohms
- On which of the following doesthe operation of a moving coil ammeterdepend?

I Electromagnetic induction.

II Force on a current-carrying

conductor in a magnetic field.

III Magnetic effect of anelectric current. A. I only B. II only

- III only D. II andIII E. I, II andIII

10 Ohms

I 5Ohms

Fig. 4

In Fig. 4, current (I) passes through the parallel

combination. If the power dissipated in the 5 ohms

V

I

V

I

V

resistor is 40W, then the power dissipated in the 10 ohms resistor is

- 10 W B. 20 W
- 40 W D. 80 W
- 100W
*NOT*correct?- A galvanometer can be converted to an
- E. I

V

Fig. 3

I

V

ammeter with a different range by

connecting a high resistance in series. B. An electric current always produces a magnetic field

- Maxwell’s screw rule states that if a corkscrew moves in the direction of the current, the hand turns in the direction of the lines offorce.
- Electromagnets are used in electric bells and telephone receivers.

- A wire
*P*has half the diameter and half the length of a wire*Q*of similar material. The ratio of the resistance of*P*to that of*Q*is - 8 : 1 B. 4 :1
- 2 : 1 D. 1 :1
- 1 :4
- The lines offorce round a straight current carrying conductor arecircular.
- A transformer has a primary coil with 500 turns and secondary coil with 2500 turns. When the voltage input to the primary coil is 120V, the output is

**671 **

- 6000V B. 600 V
- 240V D. 60 V
- 24 V
- Which of the following statements about electrolysis is
*NOT*correct? - The substances in solution in the electrolyte become ionized.
- Ions are electrically charged and are attracted towards electrodes when a

potential difference is applied.

- Ions may be discharged at the electrodes, forming bubbles or deposits.
- The mass deposited depends upon the length of time for which currentflows.
- The mass of gas set free or metal deposited is proportional to the square

of the current.

- Which ofthe following statementsis
*NOT*correct? A. The average range of distinct vision for a normal eye is from the far distance

(infinity) up to about 25cm in front ofthe

eye.

- Longsighted people have difficulty in making the eye lens sufficiently powerful

to the focus on nearby objects.

- Shortsighted people cannot accommodate distant objects.
- Longsighted people need diverging spectacles lenses.
- A person with long sight has his eye-ball too short and the image of an object is

therefore formed behind the retina.

- Which of the following features is
*NOT*a characteristic of naturalradioactivity? - Radioactivityis a nuclear phenomenon. B. Radioactivity is exhibited only by elements of mass number greater 206.
- The radioactivity of an element is affected by electric and magnetic fields in the

surroundings.

- The radioactive element is transformed into a new element.
- What is the number of neutrons in the Uranium isotope 238 X?

92

- 92
- 146
- 238
- 330
- 119

Physics 1986

- Which of the following represents the correct precision if the length of a piece ofwire is measured with a metrerule?
- 35 mm
- 35.0mm
- 35.00mm
- 35.01mm

Force

0 Extension

Fig. 1

Figure 1 is a graph of force against extension for a spiral spring. The force constant of the spring is given by the.

- Slope of the linear portion of thegraph. B. Length of the linear portion of the graph. C. Area under the linear portion ofthe graph. D. Area under the entiregraph.
- A heavy object is suspended from a string and lowered into water so that it is completely submerged. The object appears lighter because
- The density of water is less than that of the object.
- The pressure is low just below thewater surface.
- It experiences an upthrust.
- The tension in the string neutralizes part of the weight.

**672 **

- Which of the following is a derived unit? A. Kilogramme B.Metre
- Kelvin D. Newton
- Two objects, one having three times the mass of the other, are dropped at the same time from at tall building. When they are above the ground, the two objects will have the same
- Momentum
- Kinetic energy
- Potential energy
- Acceleration.

In Fig. 3, the forces F1, F2, F3, acting at O are in equilibrium. If the magnitude of F1is 10.0N and ,

the magnitude of F2is 5.0N, find the magnitude of F3.A. 26.4N B. 15.0N

- 13.2N D. 10.0N
- When a box of mass 400g is given an initial speed of 5m s-1, it slides along a horizontal floor a distance of 3m before coming to rest. What isthe coefficient of the kinetic friction between the box and the floor?

(g = 10m s-2)

- Which ofthe following isin a neutral equilibrium? A. A heavy weight suspended on a string.
- A cone resting on its slantedge.
- A heavy based table lamp.
- The beam of a balance in use.
- A ball is thrown vertically into the air with an initial velocity
*u*. What is the greatest height reached? *U**/*g

2

- 3
*u*2/2g *u*2/g*u*2/ g.

2

- Which of the following assumptions is made in a simple pendulum experiment? The
- 5/ C. 1/
- 5/

6

12

- 2/

3

3

W N

1200N

- Suspending string isinextensible
- Bob has a finitesize
- Bob has a definite mass
- Initial angle of oscillation must be large.

10cm

Q R P

10g

Fig. 2

A uniform metre rule QR is balanced on a knife edge which is 55cm from R. when a mass of 10g is hung at P asshown in Fig. 2, the mass of the metre rule is

- 550g B. 350g
- 70g D. 35g
- F1

10.0N

600

F2

O 5.0N

F3Fig. 3

Figure 4 represents a block-and-tackle pulley system on which an effort of W Newtons supports a load of 120.0N. Ifthe efficiencyofthe machine is 400, then the value of Wis

- 28.0N B. 48.0 N
- 50.0N D. 288.0N
- A constant force of magnitude
*F*acts on an object of mass 0.04kg initially at rest at a point O. Ifthe speed of the object when it has moved 50m from O is 500m s-1, what isthe value of*F*? - 0.4 N B. 100.0 N C. 250.0 N D. 1 000.0N
- A rectangular tank contains water to a depth of 2m. ifthe base is 4m x 3m, calculate the force on the base.

(Density of water = 103kg m-3, g = 10m s-2) A. 2.4 x105N B. 2.4 x 104N C. 2.0 x104N D. 1.7 x103 N

- A 1000kg elevator is descending vertically with an acceleration of 1.0ms-2, if the acceleration due to gravity is 10.0m 5s, the tension in the suspending cable is
- 1.0 N B. 10.0 N C. 9 000.0 N D. 11 000.0N

**673 **

- A ball attached to one end of a string moves anticlockwise around a circle whose centre is O. If the string suddenly breaks when the ball is at point P, along which of the following paths willit move?

F3

- A B
- Change the state of a unit mass lead at its melting point.
- Change the state of a unit mass of lead at its boiling point.
- Which of the following is common to evaporation and boiling? They
- Take place at any temperature.

C

O P

D

O P

- Are surface phenomena.
- Involve change of state
- Take place at a definite pressure.
- Mercury is suitable as a barometric fluid because

O

P

O P

it

- Expands uniformity
- Is opaque
- Is several times denser than water

- The mode of heat transfer which does not requires material mediumis
- Conduction B. Radiation C. Convection D. Propagation
- The expansion of solids can be considered a disadvantages in the
- Balance wheel of a watch
- Fitting of wheels onrims
- Firealarm
- Thermostat.

100

©

- Is a good conductor of heat
- Which of the following properties makes metals ideal for cooking utensils?
- High coefficient ofexpansion
- Good conduction of heat
- Low specific heat capacity
- Poor radiation of heat.
- A gas occupies a volume of 300cm3at a temperature of 270C. What is its volume at 540C, when the pressure is constant?
- 150cm3 B. 273cm3
- 327cm3 D. 600cm3
- When two objects P and Q are supplied with the

e r

u t

a r

e

p

90 80 70 60

same quantity of heat, the temperature change in P is observed to be twice that of Q. The mass of P is half that of Q the ratio of the specific heat capacity of P to Q is

- 1 : 4 B. 4 : 1

m

e

T

5 10

Time (min)

Fig.5

- 1 : 1 D. 2 : 1
- Which of the following is true of sound? A. Sound travels faster in air at 200Cthat at 300C. B. The frequency of a given sound wave changes when it crosses the boundary

In an experiment in which molten naphthalene is allowed to cool. The cooling curve in Fig. 5 was obtained. The temperature 800C is known as the A. Cooling temperature

- Boiling point
- Melting point
- Vaporization point
- The specific latent heat of fusion of lead is the amount of heat required to
- Melt lead at its melting point
- Heat a unit mass of lead through 10C.

separating twomedia..

- The wavelength of a given sound wave in air decreases as the temperature increases. D. Sound waves cannot be reflected.

**674 **

- 33. A pencil is placed vertically between a concave mirror and its focal point. The image of the pencil

in themirror will be

60o Reflected ray

- Real inverted anddiminished B. Virtual, inverted andenlarged C. Real, erect and enlarged.

Incident ray AIR

Glass

Refracted Ray

In Fig. 6, a ray oflight in air strikes a glass plate at an angle of incidence of 600C. The reflected ray is observed to be perpendicular to the refracted ray. What is the refractive index of the glass?

- 1.73 B. 1.50
- 0.87 D. 0.57.
- A lens of focal length 12.0cm forms an upright image three times the size of a real object. The distance between the object and the image is
- 8.0 cm B. 16.0 cm
- 24.0 cm D. 32.0 cm
- In which of the following arrangements is the wavelength in an increasing order?
- Gamma rays, infra-red rays, X-rays, radiowaves.
- Gamma rays, X-rays, infra-red rays, radiowaves.
- Radiowaves, X-rays, gamma rays, infra-red rays.
- Infra-red rays, radiowaves, X-rays, gamma rays.
- If the refractive index of glass is 1.5, what is the critical angle at the air-glassinterface?
- sin-1 ½ B. Sin-1 2/3
- Sin-1 ¾ D. Sin-1 8/9
- A dentist obtains a linear magnification of 4 of a hole in a tooth by placing a concave mirror at a distance of 2.0cm from the tooth. The radius of curvatureof the mirror is
- 5.3cm B. 3.2cm
- 2.7cm D. 1.6cm.
- What is the effect of the increase in the size of the hole of a pin-hole camera on the image? It
- Gives a blurredimage.
- Corrects for chromatic aberration
- Magnifies the image
- Brings the image into the sharper focus.
- Virtual, erect and enlarged.
- A wave of frequency 10 HZ forms a stationary wave pattern in a medium where the velocity is 20cm s-1. the distance between adjacent nodes is A. 1.0cm B. 1.5cm
- 2.0cm D. 5.0cm
- 35.

Fig. 7

In Fig. 7, a resonance tube experiment is performed using one turning fork. As the water level is lowered the first resonance is obtained when the length of the air column *l *= ë/4. The second resonance is obtained when *l *equals

- /2
- 3 /4
- 3 /2.
- Which of the following is true of the loudness of sound? It
- Depends on the square of the amplitude of the vibrating body.
- Is proportional to the distance of the observer from the source of the sound.
- Is greatest in vacuum
- Is independent of frequency.
- A man clapping his hands at regular intervals observes that the echo of a clap coincides with the next clap. If the reflecting cliff is 160m away and the speed of sound is 320m s-1, what is the frequency of the clapping?
- IHz B. 2Hz
- 4Hz D. 8Hz.

**675 **

- The vibration of an air column producesthe sound in the
- Piano B. Guitar
- Flute
- School handbell.

5

5

20

E

Fig. 8.

In Fig. 8, E is an accumulator with negligible internal resistance. Ifthe e.m.f. is 9.0V, then the total current is

- 0.3A B. 0.8A
- 1.0A D. 1.8A

R

- Which of the following if
*NOT*a part of the a.d.c. electric motor? - Field-magnet
- Armature
- Commutator
- Transfomer.
- Which ofthe following isstored by a dryLeclanche cell?
- Electrical power
- Kinetic energy
- Electric current
- Chemical energy.
- Which of the following arrangements will produce an equivalent resistance of 1.5Ù from three 1Ù resistors?

1 1 1

1 1

1

1

1

1

1

1

- 40.

3 2A

A

6

12V

Fig. 6.

- Which of the following is true of magnetism? A. Iron fillings cling mainly round the ends of a barmagnet.
- The freely suspended bar magnet comes to rest in the geographic north-south

direction.

- Like poles attract.
- Lodestone is a non-magneticoxide.
- The angle between the magnetic meridian and the geographic meridian at a locality on the earth is the
- Longitude of the locality.
- Angle ofinclination at the locality
- Latitude of thelocality

In Fig. 9, the valueof R is D. Angle of declination of the locality.

- 3 Ohms 46. The sign of the charge on a charged glass rod may B. 4 Ohms be determined with
- 5 Ohms A. A charged electroscope D. 6 Ohms B. An uncharged electroscope C. A galvanometer
- An electrometer.

**676 **

- The diagrams below depict the current inducedin a coil as a result of the relative motion between it and a bar magnet. Which ofthe diagrams illustrates the direction of the induced current?

N S

N S

N S

N S

- Ifthe inclination at Ibadan is 700S, this meansthat A. The angle between the geographic meridian and the magnetic meridian at Ibadan is 70
- The earth’s resultant magnetic intensity at Ibadan makes angle 70 with the horizontal direction
- A magnetic needle will be inclined at 70to the vertical at Ibadan.
- The north pole of a magnetic needle dips downwards at Ibadan.
- The wavelength of ultraviolet radiation is400nm. If the speed of light in air is 3 x 108m s-1, then the frequency of the ultraviolet radiation is
- 1.3x 10-15Hz B. 7.5x 105Hz C. 1.2x 1011Hz D. 7.5x 1014Hz.
- Which of the following is most strongly deflected by a magneticfield?
- gammarays
- alphaparticles
- beta-particles
- X-rays.

Physics 1987

- Which of the following units is equivalent to kg

ms-1?

- Ns-1 B. Nms
- Ns D. Js-1
- A man walks 8km north and then 5kmin a direction 600east of north. Find the distance from hisstarting point.

A.11.36km B.12.36km

C.13.00km D14.36km.

- 8

)

1

–

s

6

m

(

Y

4

T

I

C

2

O

L

E

0

V

1.0 2.0 3.0 4.0 Q

TIME (s)

The velocity – time graph above describes the motion of a particle between two points P and Q. What is the distance between P and Q?

- 17.0m B. 18.0m
- 22.5m D. 30.0m
- A jet engine develops a thrust of 270Ns when the velocity of the exhaust gases relative to the engine is 300m s-1. What isthe mass ofthe material ejected per second?
- 81.00kg B. 9.00 kg
- 0.90 kg D. 0.09 kg

5.

**677 **

- A body rolls down a slope from a height of 100m.
- Its velocity at the foot of the slope 20ms-1. What percentage of its initial potential energy is

converted into kinetic energy?

- 40% B. 35%
- 20% D. 15%

(g = 10ms-2)

M1

10 [g= 10 ms-1]

M2

Fig. 1

Figure 1 above shows two connected bodies of masses m1and m2in equilibrium under gravity.The tension in the upper string is

- (m –m )g B. m g

1 2 1

- m2g D. (m1 + m2)g.
- An elevator of mass 4800kg issupported bya cable which can safely withstand a maximum tension of

Q1

Water with hig

h

Kinetic energy

Q2

Water with low

Kinetic energy

E

Electrical Energy

Fig. 3.

60 000N. the maximum upward acceleration the elevator can have is

- 2.5m s-2 B. 5.0m s-2
- 7.5m s-2 D. 10.0ms-2 (g = 10m s-2)

10m

Fig. 2.

A 50.0kg block is dropped on a string from a point 10m above (Fig. 2). If the force constant of the spring is 4.0 x 104 Nm-1, find the maximum compression of the spring.

- 1.25m B. 0.50m
- 0.25m D. 0.05 m

(g = 10ms-2)

- A constant force of 40N acting on a body initially at rest gives an acceleration of 0.1ms-2for 4s. Calculate the work done by the force.
- 8 J B. 10 J
- 32 J D. 160J

Figure 3 above represents the main sequence of energy conversion at Kainji dam. The efficiency of the system is

- Q1 .

Q2

- E .

Q1

- E .

(Q1 – Q2)

- E .

(Q1 + Q2)

- The coefficient os static friction between a 40kg crate and a concrete surface is 0.25. Find the magnitude of the minimum force needed to keep the crate stationary on the concrete base inclined at 450to the horizontal.[g = 10ms-2]
- 400N B. 300N
- 283N D. 212N
- If a beaker is filled with water, it is observed that the surface of the water is not horizontal at the glass-water interface. This behaviour is due to A. Friction B. Viscosity C. Surface tension D. Evaporation.
- The mechanical advantage (MA) of an inclined plane depends on
- Its length
- Its height]
- The product of its length and height D. The ratio of its length and itsheight.

**678 **

- A load of5N gives an extension of0.56cmin a wire which obeys Hooke’s law. What is the extension caused by a load of 20N?
- 1.12cm B. 2.14cm
- 2.24cm D. 2.52cm.
- A cube of side 10cm and mass 0.5kg floats in a

I III P diagramP

liquid with only 1/ of its height above the liquid V V 5

surface. What is the relative density of the liquid? A. 0.125 B. 0.250

- 0.625 D. 2.500.
- The distance between the fixed points of centigrade thermometer is 20cm. What isthe temperature when the mercury level is 4.5cm above the lower mark?

II IV P P

V V

- 22.50C B. 29.00C A. I, II B. II, III C. 90.00C D. 100.00C C. II, IV D. III, IV

- A metallic strip ofiron and brass was heated. Which ofthe following diagrams accurately illustrates the shape of the strip after heating?

Brass

- Hot water is added to three times its mass of water at 100C and the resulting temperature is 200C. What isthe initial temperature ofthe hot water?
- 22,000J of heat is required to raise the temperature of1.5kg of paraffin from 200C. Calculate the specific

dagram

Iron

Iron

Brass

heat capacity ofparaffin.

- 1000C B. 800C A. 1466J kg-10C-1
- 500C D. 400C B. 2933J kg-10C-1
- 4400J kg-10C-1

Brass

Iron

Iron

Brass

- 5866J kg-10C-1
- Calculate the amount of heat required to convert 2kg of ice at –20C to water at 0 0C. (Specific heat capacity of ice = 2090J kg-1 0C-1, specific latent heat of fusion = 333kJkg-1).

- The length of a side of a metallic cube at 200Cis 5.0cm. Given that the linear expansivity of the metal is 4.0 x 10-5 k-1Find the volume of the cube at 1200C.
- 126.50 cm3 B. 126.25 cm3 C. 126.00 cm3 D. 125.00 cm3
- As a result of air at the top of a barometer, the height of the mercury column is 73.5cm when it should be 75.0cm; the volume of the space above the mercury is 8.0 cm3 Calculate the correct barometric height when the barometer reads 74.0cm and the volume of the space above the mercuryis

6.0 cm3.

- 72.0cm B. 74.5cm
- 75.1cm D. 76.0cm
- A fixed quantity of gas is subjected to various pressures P and the corresponding volumes V measured at a constant temperature. Which ofthe following graphs best represent the results?
- 666J B. 8 360J C. 666000J D. 674360J.
- In which of the following are the substances arranged in descending order of their thermal conductivities?
- Copper, steel, glass
- Steel, copper, glass
- Steel, glass, copper
- Copper, glass,steel.
- The vacuum in the Thermos flask helps toreduce heat transfer by
- Convection and radiation
- Convection and conduction
- Conduction and radiation
- Radiation only.
- Which of the following phenomena explains the fact that a house whose roof is coated with white

**679 **

paint will be cooler in the hot season than one coated with black paint?

of water is 1.33. what is the actual depth of the pool?

- Conduction B. Convection A. 0.75 m B. 1.013 m C. Refraction D. Reflection. C. 1.330 m D. 13,3000 m

- A wave has a frequency of 2 Hz and a wavelength of 30cm. The velocity of the wave is
- 60.0ms-1 B. 6.0m s-1 C. 1.5m s-1 D. 0.6m s-1
- A ray of light is incident at an angle of 300 on one top surface of a parallel-sided glass block of refractive index 1.5. The ray finally emerges from the lower surface. What is the angular deviation of the emergentray?

- A boat at anchor is rocked by waves whose crests A. 600 B. 390

are 100m apart and whose velocity is 25m s-1. At what interval does the wave crest reach the boat?

- 280 D. 00

Which tone?

2,500.00s

4.00s

of the following

instruments

75.00s

0.25s

has a pure

- Four lenses are being considered for use as a microscope objective. Which of the following focal lengths is most suitable?
- -5mm B. +5mm
- –5cm D. +5cm

- Guitar

- C. D.

Vibrating string Turning fork Siren.

- If the angle of declination in a place is 100E, calculate the true geographic bearing if the compass reads N400E.

- The lowest note emitted by a stretched string has

a frequency of 40 Hz. How many overtones are

there between 40 hZ and 150 Hz?

- 1 B. 2
- 3 D. 4.

N500E N300E

4

N400E N250E

P

- When the length I of a piece ofwire under constant 39

tension is varied, the relationship of the frequency

of vibration *f *with *l *is

*f*&*l B. f*& 1/2

1 Q

*l *

*f*&*l D. f*&1/*l*

- Which of the following statements supports the assumption that light travels in straightlines? A. Light can bediffracted
- A source of light produces distinct shadows of opaque objects
- A source of light produces interference patterns on a suitably placed screens.
- Light can be reflected.
- If an object is placed in front oftwomirrorsinclined at 900, howmanyimages will be formed?
- Five B. Four
- Three D. Two.
- An object 3.0cm high is placed 60.0cm from a converging lens whose focal length is 20.0cm. Calculate the size ofthe image formed.
- 0.5cm B. 1.5cm
- 2.0cm D. 6.0cm
- A pool of water appears to be 1.0m deep when viewed vertically from above. Ifthe refractive index

4

Fig. 4.

In Fig. 4 above, a voltage V is applied across the terminals P and Q. the voltage across the 1 resistor is

- V . B V

8 4

- V . D V

3 2

- Two capacitances of 6
*u*F and 8*u*F are connected in series. What additional capacitance must be connected in series with this combination to give a total of 3*u*F? - 3
*u*F B. 16*u*F - 24
*u*F D. 30*u*F.

**680 **

- 46. A galvanometer of resistance 20 isto be provided 41. M N with a shunt that 1/ of the whole current in a 10

circuit passes through the galvanometer. The

resistance of the shunt is

- 2.00 B. 2.22
- 18.00 D. 18.22

P–

Fig. 5

In Fig. 5 above, M and N are insulated metal spheres in contact. A negatively charged ebonite rod P is brought near M. when M and N are separated and the rod is taken away, which of the following statements is *CORRECT? *

- Both M and N have acquired negative charges
- Both M and N have acquired positive charges
- M has acquired negative charge and N positive charge
- M has acquired positive charge and N negative charge.
- When a transformer has more secondarywindings than primary winding, it
- Has a smaller seconder current
- Has a greater power output
- Is a step-down transformer
- Increases the total energy output.
- A current of 0.5A flows through a resistor when connected to a 40-V battery. How much energy is dissipated in 2minutes?
- 1 200J B. 1 500J
- 2 400J D. 96 000J.
- The direction ofthe magnetic field at a point in the vicinity of a bar magnetis
- Always towards the north pole of the magnet
- Always away from the south pole of the magnet
- Along the line joining the point to the neutral point
- In the direction the north pole of a compass needle would point.
- When two parallel wires carry currents in opposite directions, the force on either wire is
- Awayfrom the other wire
- Zero, because the currents cancel each other
- Twice as much as when the currents are in the samedirection
- Towards the other wire.
- What type of reaction is represented by the following scheme?

2 X + 2 Y 3 Z + 1 n + energy

1 1 3 0

- Fusion reaction
- Fission reaction
- Chain reaction
- Radioactivite decay.
- Which of the following statements is
*TRUE*of photoelectric effect? - It cannot occur in liquids
- The energy of the emitted electron is independent of the work function of the

surface

- The energy of the emitted electron depends on the wavelength of the

incident light

- The greater the intensity of the incident, the greater the energy of the emitted

electron.

- Isotopes are nuclei which have
- The same number of neutrons and electrons
- Equal number of electrons and protons C. The same atomic number but different number of neutrons
- The same number oftotal particles.
- A radioactive sample initially contains N atoms. After three half-lives the number of atoms that have disintegrated is
- N

8

- 3N

8

- 5N

8

- 7N

8

**681 **

Physics 1988

- Which of the following diagrams correctly represents the relationship between the time (T) 1. of swing of a simple pendulum and its length (
*l*)? - Which of the following are the correct SI units of the quantities indicated?

I N (Force)

- Nm-1(Torque)

III Watt (power)

IV kg ms-2(Momentum).

- I and IIonly
- I. II and IIIonly
- I, II and IVonly
- I and IIIonly.
- A lorry travels 10km northwards, 4km eastwards, 6km southwards and 4km westwards to arrive at a point T. What is the total displacement?
- 6km south B. 4kmnorth C. 6kmnorth D. 4kmeast.
- Two forces whose resultant is 100N, are at right anglesto each other. If one ofthem makes an angle of 300 with the resultant, determine its magnitude. A. 8.66N B. 50.0N
- 57.7N D. 86.6N
- Which of the following quantities are scalars? I Electrical potential

II Torque

III Momentum

IV Kinetic energy

- II and IIIonly
- I and Iionly
- III and Iv only
- I and Iv only.
- A particle starts from rest and moves with a constant acceleration of 0.5m s-2. The distance covered by the particle in 10sis
- 2.5m B. 5.0m
- 25.0m D. 50.0m
- When taking a penalty kick, a footballer applies a force of 30.0N for a period of 0.05s. If the mass of the ball is 0.075kg, calculate the speed with which the ball movesoff.
- 4.50m s-1 B. 11.25m s-1 C. 20.00m s-1 D. 45.00m s-1
- A 20-toothed gear wheel drives a 60-toothed one, ifthe angular speed ofthe smaller wheel is 120 rev s-1, the angular speed of the wheel is
- 3 rev s-1 B. 40 rev s-1 C. 360 rev s –1 D. 2 400 rev s-1
- 99.

x(m) 3

1

2

f(s)

The figure above show the displacement – time graphs for three different motions. Which of the following statements is correct?

- Graph 2 corresponds to the highest velocity
- Graph 1 corresponds to zero velocity C. Graph 3 correspondsto a particle moving in the negative x direction.
- Graph 2 correspondsto a particle moving in the positive xdirections.

y

x

z

**682 **

The figures above show three different ways of hanging a heavy picture from a hook. The tension in the string would be

- Greatest in X
- Greatest in Y
- Greatest in Z
- Same in each one.
- Howlong will it take a 60kg man to climb a height of22m ifhe expended energy at the rate of0.25kW? A. 5.3s
- 34.5s

15.15.

13.4cm

To gas

supply

3.5cm

diagra

m

- 41.6s
- 52.8s

[g = I0ms-2]

- A force, 10N, drags a mass 10kg on a horizontal table with an acceleration of 0.2m s-2. If the acceleration due to gravity is 10m s-2, the coefficient of friction between the moving mass and the table is

When one arm of a U-tube manometer is connected to a gas supply, the levels of mercury in the two arms of the U-tube are as shown in the diagram above. If the atmospheric pressure is 76.0cm Hg,

the gas pressure is

- 62.6cmHg B. 72.5cm Hg C. 79.5cmHg D. 85.9cm hg
- The product PV where P is pressure and V is volume has the same unit as

- 0.02 B. 0.08 A. Force B. Power C. 0.20 D. 0.80 C. Energy D. Acceleration

- Which of the following graphs correctly describes the variation of the mechanical advantage with load for a simple machine whose velocity ratio is 3?

MA MA

Load Load

MA MA

- The amount of heat needed to raise the temperature of 10kg of copper by1K is its
- Specific heat capacity
- Heat capacity
- Latent heat
- Internal heat.
- A tap supplies water at 250C while another supplies water at 750C. If a man wishes to bathe withwater at 40C, the ratio of the mass of cold water to the mass of hot water required is
- 1 : 3 B. 15 : 8
- 7 : 3 D. 3 : 1
- Which of the following graphs clearly illustrates the temperature change which takes place as a piece of ice at – 100C is heated slowly?

Load Load

- A body whose mass is 2kg and has a volume of 500cm just floats when completely immersed in a liquid. Calculate the density of the liquid.
- 4.0x 102kgm-3
- 4.0x 103kgm-3
- 1.0x 103kgm-3
- 1.0x 106kgm-3

ToC

0 t(min) ToC

0 t(min)

ToC

0 t(min)ToC

0 t(min)

**683 **

- When heat is applied to one end of a metal rod, the molecules at the other end soon begin to vibrate with greater amplitude than before because heat has been transfer by
- Radiation B. Convection C. Conduction D. Evaporation.
- Which of the following media allow the transmission of sound waves through them?

I Air

II Liquids

III Solids

- I and II only
- I and III only
- II and III only
- I, II andIII.

X

Y

The diagram above shows two waveforms X and Y.If the frequency is 30 HZ, what isthe frequency ofY?

- 12Hz B. 19Hz
- 60Hz D. 75Hz
- Which of the following properties is/are common to all waves?

I Diffraction

II refraction

III Interference

- I only B. III only
- I and III only D. I, II andIII.
- A piano wire 0.5m long has a total mass of 0.01kg and is stretched with a tension of 800N. Calculate the frequency of the wire when it sounds its fundamental note.
- 200 Hz B. 100 Hz
- 4 Hz D. 2 Hz.
- A note is called an octave of another note when A. Its frequency is twice that of the first note B. Its frequency is half that of the first note C. The notes have the same fundamental frequency
- Its periodic time istwice that of the first note.
- Which of the following factors affects the speed of sound in air?

I Temperature

II Pressure

III Frequency.

- I only B. II only
- I and II only D. II and IIIonly.
- The speed of sound in air at sea-level is 340m s-1 while that oflight is 300,000km s-1. Howfar (to the nearest metre) from the center of thunderstorm is an observer who hears a thunder 2s after a lightning flash?
- 170m B. 340m
- 600m D. 680m.
- A slight loading of a turning fork has the effect of A. Decreasing its amplitude
- Increasing its amplitude
- Decreasing its frequency
- Increasing its frequency
- Two strings of the same length and under the same tension give notes of frequencies in the ratio 4 : 1. The masses of the strings are in the corresponding ratio of
- 2 : 1 B. 1 :2
- 1 ; 4 D. 1 :16
- To obtain a magnification of 2.5, how far should an object be placed from the pole of a thin converging lens offocal length 10.20m?
- 0.13m B. 0.25m
- 0.28m D. 0.50m

M1

60o

diagram

M2

**684 **

In the figure above, what isthe angle ofreflection ofthe ray oflight at mirror M2?

opaque object when viewed through the arrangement of the filters above is

- 900 B. 600 A. Yellow B. Red C. 450 D. 300 C. Black D. Blue

- An object is place 10 cm in front of a concave mirror of focal length 15cm. What is the positive and nature of the image formed?
- 30cm and virtual
- 6cm and real
- 6cm and virtual
- 30cm and real.
- Which of the following phenomena explain the formation of amirage

I Reflection

III Refraction

III Diffraction

3

Magnetic

2

-X 1 4

north

- I and IIonly
- II and IIIonly
- I and IIIonly
- I, II andIII.
- When white light is dispersed by a spectrometer, the component having the shortest wavelength is A. Orange B. Green
- Violet D. Red.
- Which of the following statementsis
*TRUE*of ultra violet, visibleand infra-red rays? - They are all electromagnetic waveswith the same wavelength.
- Ultra-violet rays have shorter wvelenghts than infra-red rays and produce

fluorescence.

- Infra-red rays have shorter wavelength than visible light and produce the

sensation of heat.

- The wavelengths increase in the sequence: visible, ultra-violet, infra-red.

White

object

E F G

E, F and G are yellow, red and cyan transparent light filters respectively. The colour of a white

The wire X in the figure above is at right angles to the plane of the paper and carries a current into the paper. At which of the point labeled 1 – 4 will the magnetic flux density due to this current be in the same direction as that of the horizontal component of the earth’s magnetic field?

- 1 B. 2
- 3 D. 4.
- A spectrum of sunlight is said to be impure when A. It is made of only threecolours
- It has no red colour in it
- The different colours in itoverlap
- It does not contain white light.
- A cell of internal resistance 2 ohms supplies current to a 6-ohm resistor. The efficiency of the cell is
- 12.0%
- 25.0%
- 33.3%
- 75.0%
- When a resistance R is across a cell, the voltage across the terminals of the cell is reduced to two thirds of its nominal value. The internal resistance of the cell is
- 1 R

3

- 1 R

2

- 2 R

3

- R

**685 **

41R X

A

E

In the circuit above, the ammeter reads a current of 3 amps. When Ris 5 ohms and reads 6 amps when R is 2 ohms. The value of the unknown resistance X is

- 1 B. 2
- 3 D. 4
- Which of the following combinations of 2
*ì*F capacitors will give an effective capacitance of 3*ì*F acrossterminal XY? - A household refrigerator is rated 200 watts. If electricity costs 5k per kWh, what is the cost of operating it fo 20 days?
- N 4:80 B. N 48:00 C. N 480:00 D N 4 800:00
- Which of the following instruments consumesthe highest current?

Voltage Power

Instrument Rating Rating

- Electric iron 250V 1kW B. Television set 220V 110W C. Torch light 6V 30W D. Immersion

heater 110V 500W

- Which of the following ammeters may be used to measures alternating current?

I Moving-coil ammeter

II Moving-iron ammeter

III Hot-wireammeter.

- I and IIonly
- II and IIIonly
- I and IIIonly
- I, II andIII.
- The principle of operation of an induction coil is based on
- Ohm’slaw
- Ampere’s law
- Faraday’slaw
- Coulomb’slaw.
- A dynamo primarily converts
- Mechanical energy into electrical energy B. Electrical energy into kinetic energy C. Potential energy into kinetic energy D. Kinetic energy into potential energy.
- In a certain fusion reaction, a deuteron (2 H) 1

interacts with a triton (3 H) and produces an á 1

particle (4 He) and a second product. The second 2

product is

- A proton B. An electron C. A neutron D. A gamma ray.
- Which of the following symbolic representations is correct for an atom X with 22 electrons and 43 neutrons?
- 4 3 X

2 2

- 2 2 X

4 3

- 6 5 X

4 2

- 6 5 X

2 2

.

A particle is injected perpendicularly into an electric field. It travels along a curved path as depicted in the figure above. The particle is

- A gamma ray B. An electron C. A neutron D. A proton.

**686 **

Physics 1989

- Which of the following is a set of vectors?
- Force, mass and moment 6. B. Acceleration, velocity andmoment
- Mass, weight and density
- Mass, volume and density
- The magnitude of the resultant of two mutually perpendicular forces, F1 and F2 is 13N. If the

magnitude of F1 is 5N, what is the magnitude of

F2?

- 2.6 N B. 8.0 N
- 12.0 N D. 18.0 N
- Two points on a velocity-time graph have co ordinates (5s, 10m s-1) and (20s, 20m s-1). Calculate the mean acceleration n between the two points.
- 0.67ms-1 B. 0.83ms-2
- 1.50ms-2 D. 2.00ms-2

4.7. diagram

q r

p s

The figure above shows a uniform circularobject, centre Rand diameter PS. Acircular section, centre Q and diameter PRis cut away from it. If PQRS is a straight line, where is the centre of gravity of the figure?

- Q B. R
- A point between P and R
- A point between R and S.

A simple pendulum of mass m moves along an arc of a circle radius R in a vertical plane as shown in the figure above. What is the work done by gravity in a downward swing through the angle *Q*to 00?

*Q**Q*- mgR
*Q)*

A block of mass m is held in equilibrium against a vertical wall by a horizontal force. If the coefficient of friction between the block and the wall is *u*, the minimum value ofthe horizontal force is

*u*mg*u*)mg*u*)mg

*u *

- Which of the following graphs representsmotion with uniform velocity?
- A thin film of liquid is trapped between two glass plates. The force required to pull the plates apart will increase ifthe
- Surface tension of the liquid is reduced B. Perpendicular distance between the plates is increased.
- Area of the liquid surface in contact with the plates is increased
- Pressure of the air is decreased.

**687 **

- A block-and-tackle system is used to lift a load of 20N through a vertical height of 10cm. If the efficiencyof the system is 40%, how much work is done against friction?
- 80J B. 120J
- 300J D. 500J

In the figure above, W1 = 200g and W2 = 450g. Calculate the extension ofthe spring per unit load. [g = 10ms-2]

- 6.0x 10-5mN-1
- 2.5x 10-4mN-1
- 6.0x 10-4mN-1
- 2.5x 10-2mN-1
- Which ofthe following devices are used tomeasure pressure?

I Aneroid barometer

II Hydrometer

III Hygrometer

IV Manometer.

- I and III B. II andIII C. III and IV D. I andIV.
- A piece of wood of mass 40g and uniform cross sectional area of 2cm2floats upright in water. The length of the wood immersedis
- 80cm B. 40cm
- 20cm D. 2cm
- The pressure on the gas of constant gas thermometer at the ice point is 325mm of mercury and at the steam point 875mm of mercury. Find the temperature when the pressure ofthe gas is 190mm of mercury.
- 30k
- 243k
- 37.0cm
- A mass of gas at 70C and 70cm of mercury has a volume of 1200cm3. Determine its volume at270C and pressure of 75cm of mercury.
- 1 200 cm3
- 1 378 cm3
- 4 320 cm3
- 4 629 cm3
- An electric heater is used to melt a block of ice, mass 1.5kg. If the heater is powered by a 12V battery and a current of 20A flows through the coil, calculate the time taken to met the block ofice at 00C. (Specific latent heat offusion ofice = 336 x 103J kg-1).
- 76.0min
- 35.0min
- 21.0min
- 2.9min.
- From the kinetic theory of gases, temperature is a
- Form of energy and is proportional to the total kinetic energy of the molecules.
- Form of energy and is proportional to the average kinetic energy of themolecules.
- Physical property and is proportional to the total kinetic energy ofthe molecules.
- Physical property and is proportional to the average energy of themolecules.
- Which of the following correctly represents the variation of the saturated vapour pressure of water with temperature?

- 300k 19. A vibrator of frequency 60 Hz is used in

- 303k
- A column of air 10.0cmlong istrapped in a tube at 270C. What is the length of the volume at 1000C?
- 12.4cm
- 13.7cm
- 18.5cm

generating transverse stationary waves in a long thin wire. If the average distance between successive nodes on the wire is 45cm, find the speed of the transverse waves in the wire.

- 27ms-1 B. 54ms-1 C. 90ms-1 D. 108ms-1

**688 **

The air column as shown in the figure above is set into vibration by the turning fork. In this state of resonance, the waves in the air column will be A. Stationary and transverse

- Stationary and longitudinal
- Progressive and transverse
- Progressive and longitudinal.
- When the tension in a sonometer wire isdoubled, the waves in the air column will be
- B. ½

1/ 2

- D. 2

2

- In a sound wave in air, the adjacent rarefactions and compressions are separated by a distance of 17cm. If the velocity of the sound wave is 340ms-1, determine the frequency.
- 10 Hz B. 20 Hz
- 1 000Hz D. 5780 Hz
- In which of the following diagrams is the length of the tube equal to one wavelength?
- An object is placed 5.6 x 10-4m in front of a converging lens of focal length 1.0 x 10-8m. The image formedis
- Real, erect and magnified
- Virtual, erect and magnified
- Real, inverted andmagnified
- Virtual, erect anddiminished.
- The magnification of the image of an object placed in front of a convex mirror is 1/ . If the radius of 3

curvature ofthe mirror is 24cm, what isthe distance between the object and its image?

- 8 cm B. 16cm
- 24cm D. 32cm
- The plane mirrors in a kaleidoscope are usually placed
- At an angle of600
- Parallel to oneanother
- Perpendicular to one another
- At n angle of450
- A far sighted person cannot see objects that are less than 100cm away. If this person wants to read a book at 25cm, what type and focal length of lens does he need?
- Convex, 20cm
- Concave, 20cm
- Convex, 33cm
- Concave, 33cm.
- When a yellow card is observed through a blues glass, the cord would appear
- Black B. Green
- Red D. White
- Dispersion of light by a glass prism is due to the

- 24.

diagram

Light of wavelength 5000 x 10-8cm travelsin free

- Different hidden colours of the glass B. Different speeds of the various colours in glass
- Defects in the glass
- High density of glass.
- Which of the following pairs is
*NOT*part of the electromagnetic spectrum?

I Radio waves

II Beta rays

III Gamma rays

IV Alpha rays

space with a velocity of 3 x 108m s-1. What is its wavelength in glass of refractive index 1.5? A. 3333×10-8cm

- 5000×10-8cm
- 6666×10-8cm
- 7500×10-8cm
- I and II B. III andIV C. I and III D. II and IV.
- Two insulated charged spheres of different sizes and carrying opposite charges are connected together by a metallic conductor. Current will flow from one sphere to the other until both spheres

**689 **

- Carrythe same magnitude and sign of charge.
- Are at the samepotential.
- Are at the same temperature.
- Are ofthe same size.
- When a number of identical small magnets are arranged in a line, the strength of the resultant magnet
- Is largest when they are arranged end to end
- Is greatest when they are arranged parallel with like poles adjacent to each

other.

- Depends only on the number of magnets provided they areparallel.
- Is greater when the magnets are arranged on a wooden surface than on a metal

surface.

- A bar magnet is most effectively demagnetized by A. Placing it in a N – 5 position and hitting it with

a hammer.

- Subjecting it to an electric current from a

battery

In the above circuit diagrams, A is the ammeter and V the voltmeter. Which ofthe circuitsis correct for finding the value of the resistance R? A. I B. II

- III D. IV.

- Bringing its north pole in contact with the north pole of a very strong magnet
- Heating the magnet.
- The resistance of a 5m uniform wire of cross sectional area 0.2 x 10-6m2is 0.425. What is the

resistivity of the material of the wire?

- 1.10 x 10-6Ohms m
- 4.25 x 10-6Ohms m
- 2.40 x 10-7Ohms m
- 1.70x 10-8Ohmsm
- Three resistors, with substances 250Ohms 500Ohms and 1 kOhms are connected in series. A 6V battery is connected to either end of the combination. Calculate the potential difference between the ends of the 250Ohms resistor.
- 0.20V B. 0.86V
- 1.71V D. 3.43V.
- A calibrated potentiometer is used to measure the e.m.f. of a cell because the
- Internal resistance of a cell is small compared with that of thepotentiometer.
- Potentiometer has a linearscale.
- Potentiometer takes no current from the cell D. Resistance of the potentiometer is less than that of avoltmeter.

Three 2 – *u *F capacitors are arranged as shown in the above circuit. The effective capacitance between E and F is

- 0.75
*u*F - 1.33
*u*F - 3.00
*u*F - 6.00
*u*F - The function of a 5-A fuse included in a circuit supplying a household refrigerator with power is to keep the
- Temperature of the refrigerator low and constant.
- Current supplied to the refrigerator below 5A.
- Voltage supply constant
- Current supplies to the refrigerator constant and above 5A.

4

4

**690 **

The total power drawn from the cell in the circuit diagram above is

- 12W B. 24W
- 32W D. 40W
- Settle in anydirection
- Settle in a fixed direction only if conductor PQ is a magnetic material
- Settle in a fixed direction whether conductor PQ is a magnetic material or

not

- Be stationary.
- A radioactive substance has a half-life of 2 years. If the initial mass is 40g, which of the following rows correctly gives the mass of substance left at the times stated?

2Years 3year 4Years 5Years

A

20g

10g | |

20g | 10g |

20g | 15g |

- Which of the following correctly represents the relationship between the temperature rise
*è*and the current*l*in and experiment to illustrate the beating effect of the electric current? - An ammeter of resistance 0.1 ohms has a full

B

C

D

30g 0g 30g

20g 10g 0g

When a radiation strikes a metal surface, electrons maybe ejected from the metal. The maximumkinetic energy which may be acquired by an ejected electron depends on the

- Intensity of the radiation
- Source of the radiation
- Wavelength of the radiation
- Detection device for the electron.

Which of the following is *TRUE *of the particles emitted in radioactive disintegration?

- The alpha particle is the helium nucleus

H

3

2

scale deflection of 50 mA. Determine the

resultant full-scale deflection of the meter when

a shunt of 0.0111Ohms is connected across its

terminals.

- 400mA B. 450mA
- 500mA D. 550mA.
- The electrochemical equivalent ofsilver is 0.0012g/ C. If 36.0g ofsilver is to be deposited byelectrolysis on a surface by passing a steady current for 5.0 minutes, the current must be
- 6 000A B. 100A
- The alpha particle islighter than the beta particle
- The alpha particle is deflected morethan the beta particle in a magnetic field
- The beta particle is deflected more than alpha particle in a magnetic field.

Eight alpha decays and six beta decays necessary before an atom of 23 8 U achieves stability. The 9 2

final product in the chain has an atomic number of A. 70 B. 78 C. 82 D. 90.

1 A

- 10 A D.

A beam of radiation is passed between a pair of charged plates indicated in the diagram above. Beam P is undeflected while Q is deflected to the left. P and Q respectively could be

The figure above shows a conductor PQ carrying a current I in the direction shown. At a particular position near the conductor is a compass needle K. Neglecting the earth’s magnetic field, the compass needle will

- Alpharays Betta-rays II x-rays Betta-rays III. gammarays Alpha-rays IV x-rays Alpharays. A. I only B. III only C. I and II D. III and IV.

**691 **

Physics 1990

.1.

- mv .

M

- Mv .

M -m

- Mv .

M +m

- mv .

M -m

What is the reading of the vernier scale above? 6.

- 1.88 cm B. 1.80 cm
- 1.28 cm D. 1.97 mm
- Which of the following is a fundamental unit?
- Newton B. Watt
- Joule D. Second

What is the average velocity of the sprinter whose

velocity-time graph is shown in the figure above?

- 85.0m s-1 B. 17.0ms-1
- 8.5m s-1 D. 1.7m s-1
- Which of the following statements are

Two horizontal forces, 10N and 8N and another

force F, inclined at 300to the vertical acting as

shown in the diagram above, keep the body P in

equilibrium. The weight of the body is

- 2 3 N

3

- 3N
- 4 3 N

3

- 2 3 N
- A car moving with a speed of 90km h was brought uniformly to rest by the application ofthe brakes 8. X

in 10s. How far did the car travel after the brakes

were applied?

- 125 m B. 150 m
- 250 m D. 15 km
- A particle of mass M which is at rest splits up into two. If the mass and velocity of one of the particles

are m and v respectively, calculate the velocity of

the second particle.

correct about an object in equilibriumunder parallel forces? I The total clockwise moments of the forces about any point equals the total anticlockwise moments about the same point.

II The total forces in one direction equals the total forces in the opposite direction III The resolved components along the x axis equalsthe resolved component along the y-axis.

- I and II only B. I and III only C. II and III only D. I, II andIII.

2m

Y5N

Z

**692 **

A force of 5N acts at a point Y on a rod XYZ as shown in the diagram above. If XY is 2m, what is the moment of the force about pointX?

- 0Nm B. 3Nm
- 7Nm D. 10Nm.
- To keep a vehicle moving at a constant speed v, requires power P, from the engine. The force provided by the engine is
- P B. 1/2v

v

- pv D. p/v2
- P

V2

- A stone of mass m kg is held h meters above the floor for 50s. The work done in joules over the period is
- mh B. mgh
- mgh/50 D. 0
- A body of mass 10kg rests on a rough inclined plane whose angle of tilt è is variable. is gradually increased until the body starts to slide down the plane at 300. The coefficient of limiting friction between the body and the plane is
- 0.30 B. 0.50
- 0.58 D. 0.87.
- An inclined plane which makes an angle of 300 with the horizontal has a velocity ratio of
- 2 B. 1
- 0.866 D. 0.50.
- What is the length of the liquid column in a barometer tube that would support anatmospheric pressure of 102000 Nm-2if the density of the liquid is 2600 kgm-3? [g = 10 ms-2].
- 0.75m B. 0.76m
- 3.92m D. 39.23m.
- 40cm3 ofliquid is mixed with 60m3 of another liquid Q. If the density ofP and Q are 1.00kg m3and 1.6kg m3respectively, what isthe density of the mixture? A. 0.05 kg m-3 B. 1.25 kg m-3
- 1.30 kg m-3 D. 1.36 kg m-3
- The resistances of a platinum wire at the ice and steam points are 0.75 ohm and 1.05 ohm respectively. Determine the temperature at which the resistance ofthe wire is 0.90 ohm
- 43.00C B. 50.00C
- 69.90C D. 87.00C
- A bar of initial length
*l*0 is heated through a temperature change Ä t to a new length*l*. The linear expansivity, á, ofthe bar is *l – l**0**.*

*l *Ä t

*l – l**0**.*

*l**0 *Ä t

*l**0*(1 + Ät)*l – l**0**.*

*l *(1 + Ät)

- The pressure of a gas when cooled at constant volume will decrease because themolecules
- Collide less frequently with the walls of the container.
- Have the same average kineticenergy C. Break up into smaller molecules
- Decrease in number.
- 1kg of copper is transferred quickly from boiling water to a block of ice. Calculate the mass of ice melted, neglecting heat loss.
- 60g B. 67g
- 120g D. 133g
- Which of the following conditions will make water boil at a temperature of 1000C when the atmospheric pressure is 750mm Hg?
- Increase the external pressure
- Reduce the external pressure
- Heat more rapidly at the same pressure. D. Reduce the external pressure by a quarter.
- Which of the following statements are correct? I Land and sea breezes are natural convection currents.

II Convection may occur in liquids or gases but not in solids.

III The vacuum in thermos flask prevents heat loss due to convection only.

- I and IIonly
- II and IIIonly
- I and IIIonly
- I, II andIII.
- A light wave of frequency 5 x 1014 Hz moves through water which has a refractive index of 4/ . 3

Calculate the wavelength in water if the velocity oflight in air is 3 x 108 ms-1

- 4.5x 10-7m B. 6.0 x 10-7m C. 1.7x 10-6m D. 2.2x 10-6m
- A wave disturbance traveling in air enters a medium in which its velocity is less than that in air. Which of the following statements is true about the wave in themedium?
- Both the frequency of the wave and the wavelength are decreased.

**693 **

- The frequency of the wave is decreased while the wavelength isincreased.
- The frequency of the wave is unaltered while the wavelength isdecreased.
- The frequency of the wave is decreased while the wavelength isunaltered.
- Shadows and eclipse result fromthe A. Refraction oflight
- Rectilinear propagation oflight
- Defraction oflight
- Reflection of light
- An object which is 3cm high is placed vertically 10cm in front of a concave mirror. If this object produces an image 40cm from the mirror, the height of the image is
- 0.75 cm B. 4.00 cm C. 8.00 cm D. 12.00cm
- A boy looks at the image of an object in a plane mirror. He observes two images, a main bright one and the other faint. The observed images result from
- Reflection only
- Refraction only
- Diffraction and interference
- Reflection and infraction.
- Which ofthe following diagrams correctlyillustrates the path of a ray light through a glass prism?
- What must be the distance between an object and a converging lens of focal length 20cm to produce an erect image two times the object height?
- 20cm B. 15cm
- 10cm D. 5cm
- Which of the following correctly represents the diagram for locating the image P of an object O in a lens if F is the focal point of the lens?
- I and II only B. II and III only C. III and Iv only D. I and Iv only
- For a short sighted person, light rays from a point on a very distant object isfocused
- In front of the retina
- On the retina by a converging lens
- Behind the retina by a diverging lens D. In front of the retina a distance 2F from the lens.
- When light is incident on an object which is magenta in colour, which of the following colours be absorbed?
- Red and blue B. Green only C. Red and green D. Red only.
- In a resonance tube experiment, the effective length of the air column for the first resonance is 20cm when set into vibration by a tuning fork of frequency 480 Hz. Neglecting end effect, the velocity of sound in air is
- 106 Hz B. 213 Hz
- 318 Hz D. 425 Hz
- An organ pipe closed at one end is 80cm long. Determine the frequency of the fundamental note assuming that the speed ofsound in air is 340ms-1. A. 5.1N B. 7.1N
- 14.0N D. 19.6N
- One of the properties of the earth’s magnetic field is that the
- North pole liesin the northern hemisphere B. Geographic and magnetic meridians coincide
- Earth’s magnetic flux is entirely horizontal at a place where the magnetic vertical dip

is zero.

- Earth’s magnetic flux is entirely vertical at a place where the magnetic dip is zero.
- Which of the following statements are true of an insulated charged bodycarrying a positive charge? I It contains excess positive charges

II It creates an electricfield

III It possesses potential energy

IV It carries electriccurrent.

**694 **

- I and IV only B. I and II only C. I, II and II only D. I,II,III andIV.
- Which of the following is a vector?
- Electric charge
- Electric field
- Electric potential difference
- Electric capacitance.
- Three cells each of e.m.f. 1.5V and an internal resistance of 1.0 Ohms are connected in parallel across a load resistance at 2.67 Ohms. Calculate the current in the load?
- 0.26A B. 0.41A
- 0.50A D. 0.79A.
- When a known standard resistor of 2.0 Ohms is connected to the 0.0cm end of a meter bridge the balance point is found to be 55.0cm. what is the value of the unknown resistor?
- 1.10 Ohms B. 1.64 Ohms C. 2.44 Ohms D. 27.50 Ohms
- The total energy required to send a unit positive charge round a complete electrical circuit is the A. Kinetic energy
- Potential difference
- Electromotive force
- Electrical energy
- Which of the following graphs of current against voltage illustrates Ohm’slaw?
- Heat dissipation
- Production of eddy currents
- Excessive current discharged
- Excessive voltage discharged.
- A lamp is rated 240V, 60W. The resistance of the filament is
- 960 Ohms B. 16 Ohms C. 15Ohms D. 4 Ohms
- A 0 – 10 mA galvanometer with a coil resistance of 30 Ohms can be converted to a 0 –10A ammeter by using
- 0.03 ohms seriesresistor
- 0.03 ohms shunt resistor
- 9.99 ohms shunt resistor
- 9.99 ohms seriesresistor
- The number of neutrons contained in the nucleus of 32 8 U is 9

A.292 B. 146

- 238 D. 330
- What precaution should a manufacturer take to ensure that energy loss in a transformer is minimized?
- The winding of the transformer should be made of high resistancewires.
- The core should be made of thin sheets ofmetal.
- No magnetic material should be used to make the core.
- The flux linking the primary with the

v

I

v

I

secondary coils should be minimum.

- A substance has a halflife of 3 min. after 6 min, the count rate was observed to be 400. What was its count rate at zerotime?
- 200 B. 1200

v v

I I

- Which of the following is an essential physical property of the wires used for making fuses? A. Low density
- High thermal conductivity
- Low electricalresistivity
- Low melting point.
- Which of the following is most suitable for protecting the circuit of a 2000W electric iron connected to a 250V mains?
- 13A B. 8A
- 5A D. 3A
- Electrical power is transmitted at a high voltage rather than low voltage because the amount of energy loss is reduced due to
- 1600 D. 2 400
- Which ofthe following graphsrepresents a voltage current characteristics curve for a diode?
- The photocell works on the principle of the A. Voltaiccell
- Emission of electrons by incident radiation
- Emission of protons by incident electrons.

**695 **

- Photographic plate. Physics 1991

- Which ofthe following is the most suitable for use as an altimeter?
- A mercurybarometer
- A fortin barometer
- A mercurymanometer
- An aneroid barometer.
- A body of weight W N rests on a smooth plane inclined at an angle Q0to the horizontal. What is the resolved part of the weight in newtons along the plane?

Find the tensionT1in the diagram above if the system is in equilibrium.

- 200/ 3 N
- 100/ 3 N
- 300/ 3 N
- 100 N

[g = 10m s-2]

- A spring of force constant 1500 Nm-1is acted upon by a constant force of 75N. Calculate the potential energy stored in the spring.

- W sin Q B. W cosQ A. 1.9J B. 3.2J C. W secQ D. W tanQ C. 3.8J D. 5.0J

- A small metal ball is trown vertically upwards from the top of a tower with an initial velocityof20ms-1. If the ball took a total of 6s to reach ground level, determine the height ofthe tower.
- 60m B. 80m
- 100m D. 120m
- An object moves with uniformspeed round a circle. Its acceleration has
- Constant magnitude and constant direction. B. Constant magnitude and varying direction. C. Varying magnitude and constant direction D. Varying magnitude and varying direction.
- A body of mass 100g moving with a velocity of 10.0 ms-1collides with a wall. If after the collision, it moves with a velocity of 2.0ms-1in the opposite direction, calculate the change in momentum. A. 0.8Ns B. 1.2Ns
- 12.0Ns D. 80.0Ns
- T2

o

30

T1

10kg

- A wheel and axle have radiu 80cm and 10cm respectively.If the efficiencyofthe machine is 0.85, an applied force of 1200N to the wheel will raise a load of
- 8.0 N B. 6.8 N C. 8160.0N D. 9600.0N

F(N)

12 –

6 –

0 12 24

A body is under the action of a force F such that the force – displacement graph of the body is semicircular as shown above. The work done on the body by the force in moving through 24 metres is

- 36 ð J B. 72 ð J
- 144 ð J D. 288 ðJ
- A 20kg mass is to be pulled up a slope inclined at 300to the horizontal. If the efficiency of the plane is 75%, the force required to pull the load up the plane is
- 13.3 N B. 73.5 N
- 133.3 N D. 533.2 N

**696 **

- The spiral spring of a spring balance is 25.0cm long when 5N hangs on it and 30.0cm long, when the weight is 10N. What is the length of the spring if the weight is 3N assuming Hooke’s Law is obeyed?
- 15.0 cm B. 17.0 cm
- 20.0 cm D. 23.0cm

V V

- The mass of a stone is 15.0g when completely T T immersed in water and 10.0g when completely

immersed in a liquid of relative density 2.0. The

mass of the stone in air is

- 5.0g B. 12.0g
- 20.0g D. 25.0g V V
- A pilot records the atmospheric pressure outside his plane as 63cm of Hg while a ground observer T T records a reading of 75cm of Hg for the atmospheric

pressure on the ground. Assuming that the density of the atmosphere is constant, calculate the height of the plane above the ground. (Relative density ofHg= 13.0 and that of air = 0.00013)

- 1 200 m B. 6 300m C. 7 500 m D. 12800m
- In which of the following is surface tension important?
- The floating of a ship in water
- The floating of a dry needle in water C. The floating of a balloon in air
- The diffusion of a sugar solution across membrane.
- A thermometer with an arbitrary scale, S, of equal divisionsregisters –300S at the ice point and +900S at the steam point. Calculate the Celsius temperature corresponding to 600S.
- 25.00C B. 50.00C
- 66.70C D. 75.00C
- A brass rod is 2m long at a certain temperature. What is the length for a temperature rise of 100K, if the expansivity of brass is 18 x 10-6 K-1?
- 2.0036m B. 2.0018m
- 2.1800m D. 2.0360m
- What is the difference in the amount of heat given out by 4kg of steam and 4kg of water when both are cooled from 1000C to 800C?

[The specific latent heat ofsteam is 2,260,000J kg1, specific heat capacity of water is 4200J kg-1 K-1] A. 4,200J B. 2,260,000J C. 9,040,000J D. 9,380,000J

- The graphs below show the variation of volume (V) against temperature (T) in Kelvin for a given mass of gas at constant pressure. Which of the graphs depicts the behaviour of an ideal gas?
- How long does it take a 750-W heater to rise the temperature of 1kg to water from 200C to 500C? [Specific heat capacity of water = 4200J kg-1 K-1] A. 84s B. 112s
- 168s D. 280s
- The saturated vapour pressure of a liquid increases as the
- Volume of the liquid increases
- Volume of the liquiddecreases
- Temperature of the liquid decreases D. Temperature of the liquid decreases
- The absolute temperature of a perfect gas is proportional to the average
- Potential energy of the molecules
- Separation between the molecules
- Kinetic energyof the molecules
- Velocity of themolecules.
- A room is heated by means of a charcoal fire. An occupant of the room standing away from the fire is warmed mainly by
- Convection B. Radiation C. Conduction D. Reflection
- A boy timed 30 oscillations of a certain pendulum thrice and obtained 1 min. 10s, 1min. 12s and 1 min. 7s respectively. The mean period of oscillation of the pendulum is
- 0.14s B. 0.43s
- 2.32s D. 6.97s
- Which ofthe following is
*TRUE*oflight and sound waves? - They both transmit energy
- They both need a medium for

propagation

- They are both transverse waves
- Their velocitiesin air are equal.

**697 **

- The image in pin-hole camera is
- Erect and formed byrefraction through a lens
- Virtual and formed bydispersion
- Erect and gets sharper as the hole becomeslarger
- Inverted and formed by the light from each point traveling in a straightline.
- When a plane mirror at which a ray is incident is rotated through an angle Q, the reflected ray will be rotated through
- ½Q B. Q
- 2Q D. 3Q
- A trough 12.0cm deep is filled with water of refractive index 4/3. By how much would a coin at the bottom of the trough appear to be displaced when viewed vertically from above the water surface?
- 3.0cm B. 6.0cm
- 9.0cm D. 16.0cm
- In a ray diagram for a thin converging lens, a ray that is not parallel to the optic axis but passes through the optic center will
- Pass through undeviated
- Passthrough the center of curvature after refraction
- Emerge parallel to the principal axis
- Pass through the principal focus after refraction.
- Which of the following correctly describes the image of an object, 4cm from a diverging lens of focal length –12cm?
- The image is virtual, 3cm in front ofthe lens B. The image isreal, 6cm behind the lens
- The image is virtual, 6cm in front ofthe lens D. The image is real, 3cm in front ofthe lens.
- Two tuning forks of frequencies 256Hz and 260 Hz are sounded close to each other. What is the frequency of the beats produced?
- 2 Hz
- 4 Hz
- 8 Hz
- 258Hz
- A man hears his echo from a nearby hill 2s after he shouted. If the frequency of his voice is 260 Hz and the wavelength is 1.29m, how far away isthe hill?
- 330.0m B. 335.4m
- 660.0m D. 670.8m
- When the bottom tip of a vibrating turning fork held in contact with a wooden box, a louder sound is heard. This phenomena is knownas
- Beats
- Echoing
- Resonance
- Reverberation
*CORRECT*about the earth’s magnetic field?- The angle of dip is the angle which a free suspended magnet makes with the

vertical

- The angle of declination is the angle between the magnetic meridian and the

geographic meridian

- The angle of declination is the angle which a magnetic compass makes with

the magneticmeridian.

- The angle of inclination is the difference between the angle of dip and the angleof

declination.

- An insulated rod when rubbed with a material acquires
- A negative charge if it is made of glass and rubbed with silk
- No charge if it is made of glass and rubbed with fur
- No charge if it is made of copper and rubbed with silk
- A positive charge if it is made of copper and rubbed with fur.

The internal resistance of each of the cells E1 and E2 shown in the figure above is 2Ù. Calculate the total current in the circuit

- 0.80A B. 0.50A
- 0.40A D. 0.004A
- The function of the system of granulated carbon mixed with manganese (IV) oxide in a Leclanche cell is to
- Increase the e.m.f. ofthe cell to 2.0V
- Prevent local action in thecell
- Prevent polarization in the cell
- Make the cell black and hence a good radiator

**698 **

- A moving coil galvanometer of 300 Ohms resistance gives full scale deflection for 1.0mA. The resistance, R, of the shunt that is required to convert the galvanometer into a 3.0A ammeter is
- 899.70Ohms
- 10.00Ohms
- 0.10 Ohms
- 0.01 Ohms
- Which of the following obeys Ohm’s Law? A. Glass B.Diode
- All electrolytes D. All metals. 39.

The net capacitance in the circuit shown above is A. 8.0 uF B. 6.0 uF

- 4.0 uF D. 2.0 uF
- If a current carrying coil is mounted on a metal frame, the back e.m.f. induced in the coil causes A. Inductance B. Eddy currents C. Electromagnetism D. Dipole moment
- The electrochemical equivalent of platinum is 5.0 x 107 kg C-1.To plate-out 1.0kg of platinum, a current of 100A must be passed through n appropriate vessel for
- 5.6 hours
- 56 hours
- 1.4 x 104hours
- 2.0 x 104 hours.
- Which of the following statements are
*TRUE*of isotopes?

I Isotopes of an element have the same chemical properties because they have

the same number of electrons.

II Isotopes of elements are normally separated using physical properties

III Isotopes of an element have the same number of protons in the nuclei.

- I and IIonly
- I and IIIonly
- II and IIIonly

.

In the above circuit, the fuse wire melts when A. K is opened

- K is closed
- The 14 – Ohmsresistor is doubled with K closed
- The 6 – Ohms resistor is doubledwith K closed.
- I, II andIII.
- When an atom loses or gains a charge, it becomes A. An electron B. An ion
- A neutron D. A proton.
- 4g of a radioactive material of half-life 10 days is spilled on a laboratory floor. How long would it take to disintegrate 3.5g of the material?
- 1¼ days
- 8¾ days
- 30 days
- 80 days.
- In a nuclear fusion process, four protons each of mass Mp were fused to produce a nucleus X of mass Mx. Which of the following equations is
*CORRECT*?

- An equipment whose power is 1500W and resistance is 375 ohms would draw a current of A. 0.10A B. 2.00A
- 4.00A D. 77.5A.
- To convert an alternating current dynamo into a direct current dynamo, the
- Number of turns in the coil isincreased B. Strength ofthe field magnetic isincreased C. Slip rings are replaced with a split ring commutator
- Coil is wound on a soft ironarmature.
- 4 Mp> Mx B. 4 Mp =Mx C. 4 Mp< Mx D. Mp = Mx
- Which of the following are
*TRUE*for á-decay I. Mass number decreases by four

II Atomic number decreases by two

III Mass number does not change.

- I and II only B. II and III only C. I and III only D. I, II andIII.

**699 **

- Which of the following phenomena is called photoelectric effect?
- High energy electrons impinge on a metallic anode which then emits photons
- A high energy photon emits photons as it is slowed down
- A metal absorbs quanta oflight and then emits electrons
- Two electrons are created fromquantum oflight.

Physics 1992

- What is the least possible error in using rule 7. graduated in centimeters?
- 0.1cm B. 0.5cm
- 1.0cm D. 2.0cm
- Which ofthe following affectsthe period of a simple pendulum?

I Mass of the pendulum bob

II Length of thependulum

III Acceleration due to gravity.

- I, II andIII
- II and II only

- I and III only
- I and IIonly.
- A boy sitsin a train moving with uniform speed on a straight track. If from his outstretched palm he gently tosses a coin vertically upwards, the coin willfall
- In front of his palm
- Behind hispalm
- Beside his palm
- Into hispalm
- A body starts from rest and moves with uniform acceleration of 6 ms-2. What distance does it cover in the third second?
- 15m B. 18m
- 27m D. 30m
- A stone, Q is thrown with velocity u at an angle of 750to the horizontal. Another stone R is thrown with the same velocity u but at an angle of 150to the horizontal. The ranges covered by the stones will be
- Greater for Q B. Greater for R C. The same for Q and R
- Greater for heavier of the stones
- A man weighting 800N climbs up a flight ofstairs to a height of 15m in 12.5s. What is the man’s average power output?
- 667W B. 810W C. 960W D. 15 000W

A uniform light rod is kept in horizontal equilibrium under the influence of four forces as shown above. Which of the following equations correctly representsthe condition of equilibrium for the rod? A. F1 + F2 = F3 + F4

- F1 + F2 – F3 + F4 = 0
- (F + F )ab = (F + F )cd

1 2 3 4

- F1a + F2b – F3c – F4d = 0

In the diagram above, the hanging mass m2 is adjusted until m1 is on the verge of sliding. The coefficient of static friction between the mass m1 and the table is

- m1

ms

**700 **

- m1g

ms

- m2

m1

- m2g

m1

- A machine requires 1000J of work to raise a load of 500N through a vertical distance of 1.5m. Calculate the efficiency of the machine.
- A bridge made of steel is 600m long. What is the daily variation in its length if the night-time and day-time temperatures are 100C and 350C respectively. The linear expansivity of steel is 0.000012C-1.
- 0.18cm B. 1.80cm
- 18.00cm D. 1800cm
- One ofthe most important applications of bimetallic strip is found in the construction of

- 80% B. 75% A. A thermostat B. An altimeter C. 50% D. 33% C. A thermocouple D. A hygrometer

- In an experiment to determine Young’s Modulus for a wire, several; loads are attached to the wire and the corresponding extensions measured. The tensile stress in each case depends on the
- Load and the extension
- Load and the raiud of the wire
- Radius ofthe wire and the extension D. Extension and the original length of the wire.

The figure above shows the height of two liquids X and y when some air is sucked out of the apparatusthrough the pump P.the diameter ofthe tube in X istwice that ofthe Y.What is the relative density of the liquid X with respect to liquid Y? A. 1/3 B. 2/3

- 3 D. 6
- If a plastic sphere floatsin water (density = 1000kg m-3) with 0.5 of its volume submerged and floatsin oil with 0.4 volume submerged, the density of the oil is
- 800 kgm-3 B. 1 200 kgm-3 C. 1 250 kg m-3 D. 2 000 kgm-3
- A platinum resistance thermometer wire has a resistance of 5 ohms at 00C and 5.5 ohms at 100. Calculate the temperature of the wire when the resistance is 5.2 ohms
- At constant pressure, the density of a fixed mass of gas is
- Constant with temperature
- Proportional to its volume
- Inversely proportional to itstemperature D. Independent of its volume
- Howmuch heat is absorbed when a block of copper of mass 0.05kg and specific heat capacity 390J kg-1 K-1is heated from 200Cto 700C?
- 3.98 x 10-1J B. 9.75 x 102J C. 3.98x 103J D. 9.75 x 103J
- A block of ice floats on water inside a container. If the block of ice gets completely melted, the level of water in the container will
- Increase
- Remain the same
- Decrease
- First decrease and then increase.
- The space between the double glass walls of a thermos flask is evacuated and the two surfaces facing the evacuated space are silvered. The residual source of heat loss takes place by
- Convection
- Radiation from the surfaces’
- Conduction through the stopper and the glass.
- Conduction across the walls.
- The equation of wave is

y = 0.005 sin [x(0.5x – 200 t)]1

where x and y are in metres and t is in seconds. What is the velocity of the wave?

- 4 000 m s-1 B. 400 m s-1 C. 250 m s-1 D. 40 m s-1
- Which of the following characteristics of a wave is used in the measurement of the depth of the

- 800C B. 600C sea?
- 400C D. 100C A. Diffraction B. Interference C. Refraction D. Reflection

**701 **

- A note is the octave of another note if it has A. A frequency twice that of the first note B. Frequency half that of the first note C. The same frequency as the first one D. A frequency eight times that of the first note.
- What is the frequency of the sound made by a siren having a disc with 32 holes and making 25 revolutions per second?
- 80 Hz B. 600 Hz C. 800 Hz D. 1600 Hz
- Which ofthe following properties make the convex mirror useful as a driving mirror?

I The image isreal

II The image iserect

III It has a wide field ofview

IV The image is magnified

- I, II and IV B. I, II and III C. II and III D. I and III.
- When an object is placed very close tothe pole of a concave mirror, the virtual image obtained is A. Diminished andupright
- Diminished andinverted
- Enlarged and inverted
- Enlarged and upright.
- A concave mirror has a radius of curvature of 36cm. At what distance from the mirror should an object be placed to give a real image three timesthe ize of the object?
- 12 cm B. 24 cm
- 48 cm D. 108cm
- Which of the following statements is
*CORRECT*about a long-sighted boy who does not put on glasses? - He cannot see distance objects clearly
- Rays of light from a close objects are focused in front of hisretina
- His eyeball is too long
- Parallel rays of light are focused behind his retina.
- The speed oflight in air is 3 x 108 m s-1. What isthe peed in glass with a refractive index of 1.50?
- 1.5 x 108m s-1 B. 3.0 x 108m s-1 C. 2.0 x 108m s-1 D. 6.0x 108ms-1.
- Ifthe refractiveindex ofa mediumin air is 2.0, what isthe critical angle for this medium?
- Which of the following arrangements of the components of electromagnetic spectrum is in ascending order of wavelengths?
- Gamma rays, ultraviolet rays, x-rays, infra-red rays.
- Gamma rays, x-rays, ultraviolet rays,infra-red rays
- Infra-red rays, ultraviolet rays, x-rays, gamma rays.
- Gamma rays, ultraviolet rays, infra-red rays, x rays.

The diagram above represents the field pattern obtained by bringing the poles of two magnets near each other. The poles must be

- N – N poles B. S – S poles C. S – N poles D. N – S poles
- The angle between the direction of the earth’s magnetic field and the horizontal is called the
- Angle of deviation
- Magnetic declination
- Magnetic meridian
- Angle of dip
- Calculate the force acting on an electron of charge 1.6 x 10-19 C placed in an electric field of intensity 108Vm-‘.
- 1.6 x 10-11N B. 1.6 x10-14N C. 1.6 x 10-16N D. 1.0 x10-16N
- When an ebonite rod is rubbed with fur, it has A. No charge atall
- A negative charge
- A positive charge
- Negative and positive charges.
- Which of the following factors has no effect on e.m.f. of a primary cell?
- Temperature
- Size ofthe cell

- 300 B. 420 C. Nature of the plates C. 450 D. 500 D. Nature of the electrolyte.

**702 **

- A wire oflength 15mmade of a material ofresistivity 1.8 x 10-6 ohms-m has a resistance of 0.27 ohms. Determine the area of the wire
- 1.5x 10-4m2 B. 1.0x 10-4m2 C. 2.7x 10-5m2 D. 7.3x 10-5m2
- The diagram above shows a meter bridge in which two ofthe arms contain resistances R and 2 ohms. A balance point is obtained at 60cm from the left end. Calculate the value of R.
- 1.2Ohms B. 1.3 Ohms C. 3.0Ohms D. 6.0 Ohms

The circuit diagram above contains four ammeter W, X, Y and Z. Which of the following statements about the ammeter reading is correct?

- The reading of W is equal to that of Y and twice that ofX.
- The reading of y is greater than that of Z C. The readings of W and Y are equal and each is greater than that ofX.
- The reading of Z is equal to the sum of the readings of W andY.
- A 5-V battery is connected across the plates of a 2.0
*ì*F unchanged parallel plate capacitor. The charge on the capacitor after a long time is - 1.5
*u*C B. 10.0*u*C - 20.0
*u*C D. 50.0*u*C - Which of the following apparatus will require the smallest fuse rating for its protection?
- 60W,240V B. 60W, 40V C. 40W, 12V D. 40W, 5V 41. A capacitor of 10
*ì*F is connected across a cell of

12 volts as shown above. Calculate the energy stored in the capacitor.

- 7.2x 10-4J B. 1.4 x 10-3J C. 1.4x 10-4J D. 1.3 x 10-2J
- The heat produced in a conductor carrying an electric is
- Inversely proportional to thecurrent and the resistance
- Directlyproportional to the current, resistance and the time.
- Inversely proportional to the square of the resistance, current and thetime.
- Directly proportional to the square of the current, the resistance and the time.
- PQRS is a rectangular cell with PQperpendicular to the magnetic field as shown in the diagram. If a current flows in the direction PQRS, in what direction will the coilmove?
- Upwards
- Downwards
- Towards the north pole
- Towards the south pole.
- The maximum permissible current through a galvanometer G ofinternal resistance 10Ù is 0.05A. A resistance Ris used to convert G into a voltmeter with a maximum reading of 100V. Find the value of R and how it is connected to G.
- 20,000 ohmsin parallel
- 19,990 ohmsin series
- 1,990 ohms inseries
- 100 ohms inseries
- In alternating current theory, the unites of impedance, r.m.s. voltage and resonance frequency are respectively equal to
- Volt, ampere andhertz
- Ohm, volt andhertz
- Watt, ohm and radian
- Ohm, hertz andjoule.
- In A.C. circuit theory, the root mean square (r.m.s.) current, Irms, and the peak (maximum) current I0are

**703 **

related by

- I0= Irms/ 2
- Irms= I0/ 2
- Irms = 1/ I02
- I0= 1/Irms2
- Which of the following graphs correctly illustrates the number of remaining atoms during a radioactive decay.
- The threshold frequency for photoelectric effect depends on the
- Intensity of incidentlight
- Frequency of incidentlight
- Material of the photocathode
- Potential difference between the cathode and the mode
- After three half life, the function of a radioactive material that has decayed is
- 1/8 B. 1/3
- 2/3 D. 7/8
- 2 7 Al + 1 n ’! 2 4 Na + X

1 3 0 1 1

In the nuclear reaction above, the product denoted by X is

- A proton
- A gammaray
- A heliumparticle
- An alpha particle.

Physics 1993

- Which of the following quantities has the same unit as the watt?
- Force xtime
- Force x distance
- Force x acceleration
- Force x velocity
- The external and internal diameters of a tube are measured as (32 ± 2)mm and (21 ± 1) mm respectively. Determine the percentage error in the thickness of the tube.
- 27 B. 14%
- 9% D. 3%

The diagram above shows a velocity – time graph representing the motion of a car. Find the total

distance covered during the acceleration and the retardation periods of the motion.

- 75m B. 150m
- 300m D. 375m
- Two forces of magnitudes 7N and 3N act at right angles to each other. The angle è between the resultant and the 7N force is given by
- Cos Q = 3/7 B. Sin Q = 3/7 C. Tan Q =3/7 D. Cot Q= 3/7
- An earoplane lands on a runway at a speed of 180kmh-1and is brought to a stop uniformly in 30 seconds. What distance does it cover on the runway before coming to rest
- 360m B. 540m
- 750m D. 957m
- A rocket burns fuel at the rate of 10kg s-1and eject it with a velocity of 5 x 103m s-1.the thrust exerted by the gas on the rocket is
- 2.5 x 107N B. 5.0 x 104N C. 5.0 x 102N D. 2.0 x 10-3N
- The force experienced byan object of mass 60.0kg in the moon’s gravitational field is 1.002 x 103N. What is the intensity of the gravitational field? A. 0.60 N kg-1 B. 1.67 Nkg-1 C. 6.12 x 102N kg-1 D. 9.81 ms-1

**704 **

- Which of the following correctly describe the energy changes in the generation of light by a hydroelectric power station?
- Electrical mechanical potential light.
- Potential mechanical electrical light.
- Mechanical sound electrical

light

- Kinetic mechanical electrical light.
- A plane inclined at angle è has a velocity ratio of 10 : 1. The inclination ofthe plane to the horizontal is given by
- tan Q =1/10
- cot Q =1/10
- cos Q= 1/10
- sin Q=1/10
- A weightless vessel of dimensions 4m x 3m x 2m is filled with a liquid of density 1000 kgm-3and sealed. What is the maximum pressure this contain can exert on a flatsurface?

[g = 10 ms-2]

- 9 x 104 Nm-2 B. 4 x 104Nm-2 C. 3 x 104 Nm-2 D. 2 x 104Nm-2

In the figure above the weight X is held in position by pulling the rope KLM in the direction LM. Which of the following diagrams shows the force acting at pointL

In the diagram above, a lever of length 200m is used to lift a load of mass 180kg. The pivot at P is 120m from the load. What minimum force, F1 must be applied at the end of the lever?

- 9 N B. 18 N
- 20 N D. 200N
- An object of mass 400g and density 600 kgm-3is suspended with a string so that half of it if immersed in paraffin of density 900 kgm-3. The tension in the string is
- 1.0N B. 3.0N
- 4.0N D. 5.0N
- The thermometric property ofthe thermocouple is that its
- e.m.f. changes withtemperature
- Resistance changes with temperature C. Volume changes with temperature
- Pressure changes with resistance.
- A metal rod 800mm long is heated from 100C to 950C. Ifit expands by.36mm, the linear expansivity of the metalis
- 2.0 x102K-1 B. 2.0 x10-2K-1 C. 5.0 x10-2K-1 D. 2.0 x 10-5K-1
- When the volume of a given mass of gas in halved and its temperature doubled, the pressure
- Remains constant
- Increases by a factor of 4
- Increases by a factor of 3
- Decreases by a factor of 4
- 200g of water at 900Cis mixed with 100g of water at 300C. What is the final temperature?
- 500C B. 600C
- 700C D. 800C
- A block of ice at 00C is put in an open vessel and heated uniformly until half the water boils off.

**705 **

Which of the following graphs best illustrates the change in temperature during the process?

- The melting point of a solid is given at 800C. if 105J of heat energy is required at this temperature to melt 10g of the solid, the specific latent heat of fusion of the solid is
- 1.00 x 103J kg-1
- 1.25 x 105 J kg-1
- 1.00 x 107J kg-1
- 8.00 x 108J kg-1

**Use the figure below which shows a stationary wave in a closed tube to answer questions 20 and 21. **

- The relationship between L and the wavelength ë of the stationary wave is
- Acoustic waves
- Infra-red waves
- Radio waves emitted from an antenna are picked up by a radar after reflection from an aircraft in 4 x 10-ss. How far isthe aircraft from the antenna? [c = 3 x 108 ms-1]
- 6.0 x 102 km B. 1.2 x 103 km C. 3.0 x 103 km D. 6.0 x 105 km
- The fundamental frequency of vibration (f) of a wire is measured as a function ofthe tension (T) in the wire. Which ofthe following curves adequately represents the data?

Twomirrors, M1, M2are inclined at right angles as shown above. Calculate the angle of reflection of the ray oflight at mirror M2.

- 300 B. 450

- B.

2L= L=

- 600 D. 900
- Which of the following expressions gives the linear

- L = /3
- 4L= 3
- Determine the distance between the consecutive antinodes XX ifthe wavelength is 66cm.
- 15 cm B. 30cm
- 60cm D. 120cm
- Which of the following waves can propagate through a vacuum?
- High velocity sound waves
- Ultrasonic waves

magnification produced by a concave mirror of radius of curvature r, if u and v are theobject and image distances respectively?

- v 1

r

- 2 v 1

r

- u 1

r

- 2u 1

r

**706 **

- If the focal length of a camera lens is 20cm, the distance from the film at which the lens must be set to produce a sharp image of an object 100cm away is
- 17cm B. 20cm
- 25cm D. 100cm
- Which of the following may be used to explain a mirage?

I Layers of air near the road surface have varying refractiveindices in hot weather

II Road surfaces sometimes becomes good reflectors in hot weather.

III Light from the sky can be reflected upwards after coming close to the road

surface.

- II only
- II and IIIonly
- I and IIIonly
- I, II andIII.
- A beam of light is incident from air to, water at an angle 300, Find the angle of refraction if the refractive index of water is 4/3.
- 150 B. 180
- 220 D. 240
- The property of the eye known as its power of accommodation is controlled by the
- Pupil B. Vitreous humour
- Iris D. Ciliarymuscles
- Which of the following correctly explains(s) why a green leaf appears green in bright daylight? I It absorbs only the green component of sunlight.

II It absorbs all colours in sunlight except green.

III It reflects only the green component of sunlight.

- I only
- II only
- I and IIIonly
- II and IIIonly.
- A field that results from the contact of a positively charged ball with the inner wall of an uncharged hollow conducting sphere is
- Inside the sphere
- On the surface of the ball
- Inside and outside the sphere
- Outside the sphere.
- A horizontal component of the earth’s magnetic field and the magnetic field of a straight wire X carries current into the plane of a paper. Which of the following figures correctly illustrates the

resultant magnetic field pattern in the horizontal plane?

- Which of the following correctly explain(s) why soft iron is preferred to steel in electromagnets? I Soft iron is more readilymagnetized than steel.

II Soft iron is more readily demagnetized than steel.

III Soft iron retains magnetism more than steel.

- I only
- II and IIIonly
- I and IIonly
- I, II andIII.
- A current-carrying conductor experiences a force when placed in a magnetic field because the
- Conductor is magnetized
- Magnetic field of the current interacts with external magneticfield.
- Force is due to the motor principle
- Electric field ofthe current interacts with the external magneticfield.
- A simple cell with mercury-amalgamated zinc electrode prevents
- Local action B. Polarization C. Buckling D. Degradation.
- The terminal voltage of a battery is 4.0V when supplying a current of 2.0A, and 2.0V when supplying a current of 3.0A. The internal resistance of the battery is
- 0.5 Ohms
- 1.0 Ohms
- 2.0 Ohms
- 4.0 Ohms

**707 **

The current 1 in the figure above is

- 4.00A B. 1.30A
- 0.80A D. 0.75A
- A current of 100mA passes through a conductor for 2 minutes. The quantity of electricity transported is
- 200C B. 50C
- 12C D. 0.02C
- A parallel plate capacitor of area 10cm2in vacuum has a capacitance of 10-2uF. What is the distance between the plates?

(*S *= 9 x 10-12 Fm )

0

- 9 x10-13m B. 9 x 107m C. 9x 10-3m D. 9×107m
- The primaryaim in high tension transmission isto
- Minimize electrical energy losses due to heat production
- Increase the rate of energy transfer by using high voltage
- Increase the current in the wires.
- Generate electricity at high current and low voltage.
- Determine the inductive reactance when a 30.0mH inductor with a negligible resistance is connected to a 1.30 x 103 Hz oscillator.
- 39.0 Ohms
- 122.5Ohms
- 245.0 Ohms
- 39000.0Ohms
- Which of the following statements correctly describe(s) cathode rays?

I They consist of tiny particles negative electric charges

II They are deflected in a magnetic field but not in an electric field

III Theyconsist offast moving neutrons and deflected in an electricfield.

- I only
- III only
- I and IIonly
- II and IIIonly
- Which ofthe following are produced after a nuclear fusion process?

I One heavy nucleus

II IV

Neutrons Energy

III Protons

In the network shown above, determine the

potential difference across the 5ìF capacitor. A. 3V B. 6V

- 12V D. 18V
- A 40-W instrument has a resistance of 90 ohms. On what voltage should it be operated normally? A. 60V B. 150V
- 225V D. 3600V
- Which of the following devices may be used to set u p the voltage in d.c. circuit?
- A step-up tranformer
- A d.c. generator
- A wattmeter
- An induction coil.
- I and II B. I and Iv
- II and III D. II and IV.
- An element X of atomic number 88 and mass number 226 decaysto forman element Zbyemitting two beta particles and an alpha particles. Z is represent by
- 22 2 Z

8 2

- 22 2 Z

8 8

- 22 6 Z

8 6

- 22 6 Z

8 0

- The kinetic energy of a photoelectron liberated from a metallic surface depends on the
- Intensity of the incident radiation
- Time duration of the incidentradiation C. Temperature of the incidentradiation D. Frequency of the incident radiation

**708 **

- 1cm 2cm 5cm

Physics 1994

- A stone thrown vertically upwards returns to the ground. Which of the following figures represents

the velocity-time graph?

What is the reading of the vernier capilers shown above?

- 1.79 cm B. 1.73 cm
- 1.39 cm D. 1.34 cm
- If it takes 5.0 hours to drain a container of 540.0 cm3 of water, what isthe flowrate of water from the container in kgs-1?
- 32.5 B. 31.5
- 30.8 D. 30.0

(Density of water = 100 kgm-3)

- A boat travels due east at a speed of 40 ms-1. What is the resultant speed of the boat?
- 1.3 ms-1 B. 10.0ms-1 C. 50.0 ms-1 D. 70.0ms-1
- An object is projected with velocity of 80 ms-1at an angle of 30oto the horizontal. The maximum height reached is
- 20 m B. 80 m
- 160 m D. 320 m
- A motor vehicle is brought to rest from a speed of 15 ms-1in 20 seconds. Calculate the retardation. A. 0.75 ms-2 B. 1.33 ms-2 C. 5.00ms-2 D. 7.50ms-2
- Which ofthe following isTRUE of a particlemoving in a horizontal circle with constant angular velocity?
- The energy is constant but the linear momentum varies
- The linear momentum is constant but the energy varies.
- Both energy and linear momentum are constant.
- The speed and the linear velocity are both constant.
- The diagram above shows a uniform wood of weight 200 N and length 50 m. it is pivoted at one end and suspended by a cord at the other end at an angle of 30oto the wood. Calculate the tension in the cord if the wood is horizontal.
- 10 N B. 20 N
- 100N D. 200N
- An object of mass 50 kg is released from a height of 2 m. find the kinetic energy just before it strikes the ground.
- 250 J B. 1 000 J C. 10 000 J D. 100 000 J
- A cone in an unstable equilibrium has its potential energy
- Decreased B. Increased C. Unchanged D. Oscillating

**709 **

- Calculate the magnitude of the force required to just move a 20 kg object along a horizontal surface ifthe coefficient offriction is 0.2
- 400.0N B. 40.0 N
- 4.0 N D. 0.4 N
- Calculate the velocity ratio of a screw jack ofpitch 0.3 cm if the length of the tommy bar is 21 cm. A. 1

140

- 14
- 70
- 140
- Which of the following graphs correctly represents the relationship between the load and the velocity ratio of a machine?
- A spring of length 25 cm is extended to 30 cm by a load of 150 N attached to one of its ends. What is the energy stored in the spring?
- 3750J B. 2500J
- 3.75 J D. 2.50 J

In the diagram above, if the atmospheric pressure is 760 mm, the pressure in the chamber G is

- 660mm B. 690mm
- 830mm D. 860mm
- A force of 15 N stretches a spring to a total length of 30 cm. An additional force of 10 N stretches the spring 5 cm further. Find the natural length ofthe spring.
- 25.0cm B. 22.5cm
- 20.0cm D. 15. 0cm
- Which of these statements are TRUE of pressure in liquids?

I Pressure acts equally in all

directions.

II Pressure decreases with depth.

III Pressure at the same level of a

liquid isthe same.

IV Pressure is dependent on the

cross-sectional area of the

barometer tube.

- I and IIIonly.
- I, II and IIIonly.
- I, II and IVonly.
- I, II,III and IV.
- The mass of a specific gravity bottle is 15.2 g when it is empty. It is 24.8 g when filled with kerosene and 27.2 g when filled with distilled water. Calculate the relative density of kerosene.
- 1.25 B. 1.10
- 0.90 D. 0.80
- If a solid X floatsin liquid P ofrelative density 2.0 and in liquid Q of relative density 1.5, it can be inferred that the
- Weight of P displaced is greater than that of Q
- Weight of P displaced is less than that of Q
- Volume of Pdisplaced is greater than that of Q
- Volume of P displaced is les than that of Q.
- The melting point of naphthalene is 780C. What is this temperature inKelvin?
- 100 K B. 315 K
- 378 K D. 444 K
- A motor tyre isinflated to pressure of2.0 x 105 Nm 2 when the temperature of air is 27oC. What will be the pressure in it at 87oC assuming that the volume of the tyre does not change?
- 2.6x 105Nm-2 B. 2.4x 105Nm-2 C. 2.2x 105Nm-2 D. 1.3x 105Nm-2

**710 **

- When 100 g of liquid L at 78oC was mixedXg of 1

liquid L at 50oC, the final temperature was 66oC. 2

Given that the specific heat capacity of L2 is half that of L1, findX.

- 50 g B. 100 g
- 150 g D. 200 g
- A volume ofwater is heated from0oCto 15oC.Which of the following diagrams correctly represents the variation ofthe volume with temperature?

.

- Heat is supplied to a test tube containing 100 g of ice at its melting point. The ice melts completelyin 1 min. what is the power rating of the source of heat?
- 336W B. 450W
- 560W D. 600W

(Latent heat of fusion of ice = 336 Jg-1)

- If a room is saturated with water vapour, the temperature of the roommust be
- at 00C
- above the dew point
- at 1000C
- below or at the dew point.
- Which of the following graphs represents the variation of pressure P against volume V at constant temperature?
- Two similar kettles containing equal masses of boiling water are placed on a table. If the surface of one is highly polished and the surface of the other is covered with soot, which of the following observations is correct?
- The equation of a transverse wave traveling along a string is given by y = 0.3 sin (0.5x – 50t) where y and x are in cm and t is in seconds. Find the maximum displacement of the particles from the equilibrium position.
- 50.0 cm B. 2.5 cm
- 0.5 cm D. 0.3 cm
- The sound from a source traveled to the bottom of the sea and the echo was heard 4s latter. If the speed of sound in sea water is 1500 ms-1,the depth of the sea is
- 6000 m B. 3000 m
- 1500 m D. 375 m
- The fundamental frequency of vibration of a sonometer wire may be halved by
- Doubling the length of the wire
- Doubling the mass of the wire
- Reducing the tension by half
- Reducing the absolute temperature by half.
- A pipe of length 45 cm is closed at one end. Calculate the fundamental frequency of the sound wave generated in the pipe if the velocity ofsound in air is 360 ms-1(Neglect end corrections).
- 55. Hz B. 148.5 Hz C. 200.00Hz D. 550.0 Hz
- The note produced by a stretched string has a fundamental frequency of 400 Hz. If the length of the string is doubled while the tension in the string is increased by a factor of 4, the frequency is
- 200Hz B. 400 Hz
- 800Hz D. 1600Hz
- To produce a parallel beam of light from a concave mirror, the distance at which the lamp should be placed from the mirror is equal to
- the focal length
- two times the focal length
- the distance of the image
- two times the radius of curvature.

**711 **

- Light of frequency 6.0 x 1014 Hz traveling in airis transmitted through glass of refractive index 1.5. Calculate the frequency of the light in the glass. A. 4.0 x 1014Hz
- 6.0x 1014Hz
- 7.5x 1014Hz
- 9.0x 1014Hz
- An object is placed in front of a converging lens of focal length 200 cm. The image is virtual and has a magnification of 2. what is the distance of the object from the lens?
- 5 cm B. 10cm
- 30cm D. 40cm
- An object is placed directly below a glass block of thickness 3.0 cm. Calculate the lateral displacement of the object if the refractive index of the glass is 1.5
- 1.0 cm B. 1.5 cm
- 2.0 cm D. 2.5 cm
- In a projection lantern offocal length ƒ, the object distance u, is such that
- u > 2ƒ > ƒ
- u < ƒ < 2ƒ
- u = ƒ < 2ƒ
- ƒ < u < 2ƒ
- Ifthe Nigerian flag (green, white, green) is viewed in pure yellow light, which of the following set of colours would be observed on the flag?
- Green, yellow,green
- Red, yellow,red.
- Black, yellow, black.
- Green, white, green.
- Which of the figures below illustrates the dispersion of white light through a triangular glass prism?
- Which of the following has the lowest internal resistance when new?
- Leclanche cell. B. Danielcell.
- Accumulator D. Torchbattery.
- When biro pen rubbed on a dry silk cloth is moved very closed to a piece of paper on a dry table, the pen is found to pick up the paper. This isbecause A. Both the pen and the cloth aremagnetized B. The pen is magnetized but the cloth is not
- The pen is charged while the cloth is magnetized
- Both the pen and the cloth are charged. 42.

In the figure above, XY is of length 1m. The value of R at balance point Z is

- 3.0 Ohms
- 13.3 Ohms
- 15.0 Ohms
- 30.0 Ohms
- Acapacitor 8 uF, is charged to a potential difference of 100V. The energy stored by the capacitor is A. 1.0 x104J B. 8.0 x 10 J
- 1.25 x10J D. 4.0 x 10-2J
- Two resistors, R1 = 4Ohms and R2 = 5 Ohms, are connected in parallel across a potential difference. If P1 and P2 represent the power dissipated in R1 and R2 respectively, the ratio P1 😛2is
- 4 :5
- 5 :4
- 16 :25
- 25 :16

**712 **

In the circuit diagram above, calculate the current in the 12 – Ohmsresistor if the cell has an e.m.f. of 12V and an internal resistance of 1 ohms.

- 0.8A B. 1.0A
- 1.6A D. 2.4A
- Which of the following are found in the receiver but not in the microphone of a telephone handset? I Diaphragm

II Soft iron ole pieces.

III Permanent magnet.

IV Carbon blocks

- I andII
- I andIV.
- II andIII
- III and IV.
- If two parallel conductors carry currents flowing in the same direction, the conductors will
- Attract each other
- Repel each other
- Both move in the same direction
- Have no effect on each other.
- A certain radioisotope of 235U emits 92

four alpha particles and three beta particles. The mass number and the atomic number of the resulting element respectively are

- 219 and 87
- 84 and 223
- 223 and 87
- 219 and 81

In the curve above, PQRST represents an alternating voltage frequency 50 Hz. The time interval between point P and R on the graph is

- 25 s
- 1 S

50

- 1 S

100

- 1

S

200

- If the light with photon energy 2 eV is incident suitably on the surface of a metal with work function 3 eV,then
- No electron will be emitted
- The few electrons emitted will have a maximum kinetic energy of1 eV
- The few electrons emitted will have a maximum kinetic energy of3 eV
- Many electrons will be emitted.

**713 **

Physics 1995

- Which of the following is the dimension of pressure?
- ML-1T-2 B. MLT-2
- ML2T-3 D. ML-3
- The length of a displaced pendulum bob which passes its lowest point twice every second is A. 0.25m B. 0.45m
- 0.58m D. 1.00m

[g =10ms-2]

In the diagram above, P, Q and R are vectors.Which of the following options gives the correct relationship between the vectors?

- P = Q + R B. P = Q – R C. P = R– Q D. P + Q + R = 0

The value of T in the figure above is

- 10.0N B. 11.8N
- 20.0N D. 40.0N
- When a ball rolls on a smooth level ground, the motion of its centre is
- Translational B. Oscillatory C. Random D. Rotational
- The velocity-time graph of a body moving in a straight line and decelerating uniformly to rest is represented by

The acceleration of the system shown above is A. 2 ms-2 B. 4 ms-2

- 6 ms-2 D. 8 ms-2
- What is the acceleration due to gravity ‘g’ on the moon, if g is 10ms-2 on the earth?
- 0.10 ms-2 B. 0.74ms-2 C. 1.67 ms-2 D. 10.00 ms-2
- A body is projected from the earth’s surface with the intention of letting it escape from the earth’s gravitational field. What is the minimum escape velocity of the body?
- 14km s-1 B. 13 km s-1 C. 12 km s-1 D. 11 km s-1

**714 **

- A uniform rod PQ of length 1m and mass 2kg is pivoted at the end P. If a load of 14N is placed at the centre of the rod, find the force thatshould be applied vertically upwards at Q to maintain the rod in equilibriumhorizontally.
- 68N B. 28N
- 17N D. 7 N

[g = 10 ms-2]

- A vehicle of mass m is driven by an engine of power P from rest. Find the minimum time it will take to acquire a speed v.
- mv2

P

- mv2

2P

- mv

P

- mv

2P

A box of mass 40 kg is being dragged along the floor by a rope inclined at 600to the horizontal. The frictional force between the box and the floor is 100N and the tension on the rope is 300N. How much work is done in dragging the box through a distance of 4m?

- 680J B. 400J
- 200J D. 100J
- Which ofthe following statements are
*TRUE*about frictional force?

I It is always a disadvantage

II It is sometimes a disadvantage

III It always exists where there is a relative motion of two bodiesthat are in contact.

IV It is sometimes very useful.

- The energy contained in a wire when it is extended by0.02m by a force of 500 N is
- 5 J B. 10 J
- 103J D. 104J
- Which of the following levers has the greatest mechanical advantage?
- A hydraulic press has a large circular piston of radius 0.8m and a circular plunger ofradiu 0.2m. A force of 500N is exerted by the plunger. Find the force exerted on the piston.
- 8 000 N B. 4 000 N
- 2 000 N D. 31 N
- The volume of an air bubble increases from the bottom to the top of a lake at constant temperature because
- Atmospheric pressure acts on the surface of the lake.
- Pressure increases with depth of the lake. C. Density remains constant with pressure
- The bubble experiences an upthrust.
- Temperature is a measure of the
- Quantity of heat transferred into the molecules of an object
- Mean kinetic energy of any molecules of the object
- Kinetic energy of any individual molecules of the substance.
- Amount of work done by the molecules of the object.
- A rectangular metal block of volume 10-6m3at 573K. If its coefficient of linear expansion is 1.2-x-10-5K-1, the percentage change of its volume is
- 1.5 % B. 1.1 %
- 0.4 % D. 0.1 %

**715 **

- A piece of wood floats inside water at room temperature with a fraction of it above the liquid surface. As the temperature of the water is raised,

the part of the wood above the density of liquid will

- Decrease because the density of water decreases with temperature.
- Increases because the density of water decreases with temperature.
- Decreases because the density of water increases with temperature
- Increase because the density of water increases with temperature.
- The equation PxVyTz = constant is Charles’ law when
- x = 1, y= -1, z = 1
- x = 0, y= 1, z = -1
- x = 1, y= 0, z = -1
- x = 0, y= 1, z = 1.
- An electric kettle with negligible heat capacity is rated at 2000 W. If 2.0kg of water is put in it, how long will it take the temperature of water to rise from200Cto 1000C?
- 420s B. 336s
- 168s D. 84s.

[specific heat capacity of water = 4200 J kg-1 K-1].

- A temperature scale has a lower fixed point of40mm and an upper fixed point of 200mm. What is the reading on this scale when a thermometer read 600C?
- 33.3 mm B. 36.0 mm C. 96.0 mm D. 136.0 mm
- A quantity of ice at -100C is heated until the temperature of the heating vessel is 900C. Which of the following constant is
*NOT*required to the vessel? - Specific heat capacity ofice
- Specific heat capacity ofwater
- Specific latent heat offusion
- Specific latent heat of vaporization.
*TRUE*differences between evaporation and boiling

I Evaporation occurs at all temperatures while boiling occurs at a fixed temperature

for a given pressure.

II Evaporation is a surface phenomenon while boiling is an interior phenomenon.

III Evaporation is affected by surface areas which boiling is not.

- I and IIonly
- I and IIIonly
- II and IIIonly
- I, II andIII.
- A well=lagged bar of length 100cm has its ends maintained at 1000C and 400C respectively. What is the temperature at a point 60cm from the hotter end?
- 580C B. 620C
- 640C D. 760C
- Which of the following is the exclusive property of a transverse wave?
- Diffraction B. Refraction C. Compression D. Polarization
- The wavelength of signal from a radio transmitter is 1500m and the frequencyis 200kHz. What is the wavelength for a transmitter operating at 1000kHz? A. 7500m B. 300m
- 75 m D. 15 m
- The difference between sound waves and light waves is that sound waves
- Are transverse while light waves are longitudinal.
- Require a medium to travel while light waves do not.
- Can be diffracted but light waves cannot D. Cannot be reflected but light waves can.
- Which of the diagrams below represents the second overtone of a vibrating string fixed at both ends?
- The pitch of an acoustic device can be increased by
- Increasing the frequency
- Increasing the amplitude
- Decreasing the loudness
- Decreasing the intensity
- Total eclipse of the sun occurs when the A. Earth is between the moon and the sun B. Sun is between the moon and the earth C. Moon is between the sun and the earth D. Ozone layer isthreatened

**716 **

- What is the approximate critical angle for total internal reflection for diamond if the refractive index of diamond is 2.42?
- 210 B. 220
- 230 D. 240
- Which of the graphs represents the relationship between
*m*and*v*for a convergingmirror? - A real object is placed at a distance
*u*cm in front of a curved mirror of focal length*f*cm. If the image is upright and magnified, then the mirror is *u*=2*f**u*= 2*f*

* f** *

- Convex and
*u*=2

*f** *

- Concave and
*u*= 2 - Which of the following pairs of colours gives the widest separation in the spectrum of white light? A. Red and violet
- Green and yellow
- Red and indigo
- Yellow andviolet.
- Two parallel plates at a distance of 8.0 x 10-3m apart are maintained at p.d. of 600 volts with the negative plate earthed. What is the electric field strength? A. 4.8 Vm-1
- 75.0Vm-1
- 4800.0 Vm-1
- 7,5000.0Vm-1
- At different locations on the earth’s surface, the earth’s magnetic fieldis
- The same in magnitude and direction
- The same in magnitude but different in direction
- Different in both magnitude anddirection D. Different in magnitude but not indirection.
- If a resistance if halved in value and the potential difference across it is tripled, then the ratio of the new current to the old is
- 1 : 6 B. 1 : 3
- 2 : 1 D. 6 : 1
- A 12-V battery has an internal resistance of 0.5 ohms. If a cable of 1.0 ohmsresistance is connected across the two terminals of the battery, the current drawn from the batteryis
- 16.0A B. 8.0A
- 0.8A D. 0.4A
- The diagram above shows two similar bulbs X and Y connected to a suitable power supply with F as an appropriate fuse rating. If the filament of X breaks, then the
- Brightness of Y will reduce
- Brightness ofY will remain constant C. Brightness ofY will remain constant D. Fuse F will blow.
- The purpose of a dielectric material in a parallel plate capacitor is to
- Increase its capacitance
- Decrease its capacitance
- Insulate the plates from each other
- Increase the magnetic field between the plates.

The resultant in the figure above is

- 15.0 uF B. 9.8 uF
- 1.3 uF
- 0.8 uF
- An electric current of 2 amperesflowsin a heating coil ofresistance 50 ohmsfor 3 minutes 20 seconds. Determine the heat produced.
- 0.5 kJ B. 8.0 kJ
- 20.0kJ D. 40. 0kJ
- If the maximum voltage across a 100-ohm resistor is 20V, then the maximum power it can dissipate is A. 5.00W B. 4.00W

**717 **

- 2.00W D. 0.25W
- Which of the following is required to convert a milliammeterto an ammeter?
- A high resistance in parallel
- A high resistance in series
- A low resistance in parallel
- A low resistance inseries.
- The primarywinding of a transformer has 400 turns and its secondary has 100 turns. If a source of e.m.f. of12Vis applied to the primary, the secondary e.m.f. will be
- 3 V B. 6 V
- 24V D. 48V
- An alternating source is connected in series to a capacitor of capacityreactanceof 103 3 and resistor of a resistance 103 Ohms. The impedance of the circuit is
- 2000 3Ohms
- 2000Ohms
- 1000 3Ohms
- 1000Ohms
- The half-life of a radioactive element is 9 days. What fraction of atoms has decayed in 36 days? A. 1

16

- 1

4

- 1

2

- 15

16

- A light of energy 5eV falls on a metal and the electrons with a maximum kinetic energy of 2eV are rejected. The work function ofthe metal is A. 0.4eV B. 2.5eV
- 3.0eV D. 7.0eV

Physics 1997

- At what respective values of X, Y and Z would the unit of force, the Newton, be dimensionally equivalent to MxLyTz?
- -1, 1, 2
- 1, 2, -2
- 1, -1, 2
- -1, 1, -2
- The distance xm traveled by a particle in time t secondsis described by the equation x = 10 + 12t². Find the average speed of the particle between the time interval t =2s and t = 5s.
- 60 ms-1 B. 72 ms-1 C. 84 ms-1 D. 108 ms-1
- A 5kg block isreleased from rest on a smooth plane inclined at an angle of 30o to the horizontal. What is its acceleration down the plane?
- 5.0 ms-2 B. 5.8 ms-2 C. 8.7 ms-2 D. 25.0 ms-2 [g = 10 ms-2]
- An arrow of mass 0.1kg moving with a horizontal velocity of 15 ms-1 is shot into a wooden block of mass 0.4 kg lying at rest on a smooth

horizontal surface. Their common velocity after impact is

- 15.0 ms-1 B. 7.5 ms-1 C. 3.8 ms-1 D. 3.0ms-1
- Two bodies X and Y are projected on the same horizontal plane, with the same initial speed but at angles 30o and 60o respectively to the horizontal. Neglecting air resistance, the ratio of the range of X tothat of Y is
- 1:1 B. 1 :2
- 3 : 1 D. 1 :3
- Which of the following with respect of a body performing simple harmonic motion are in phase? A. Displacement and velocity of the body. B. Displacement and force on the body C. Velocity and acceleration f the body. D. Force acting on the body and the acceleration.
- A body of mass 2 kg moving vertically upwards has its velocity increased uniformly from 10 ms-1 to 40 ms-1in 4s. Neglecting air resistance,calculate the upward vertical force acting on the body.
- 15N B. 20N
- 35N D. 45N

[g = 10 ms-2]

- A planet has mass m1 and is at a distance r1 from the sun. A second planet has mass m2 = 10m1 and is at a distance of r2 = 2r1 from the sun.Determine

**718 **

the ratio of the gravitational force experienced by the planets.

- 1 : 5 B. 2 :5
- 3 : 5 D. 4 :5
- T = 5 3 F 3
- T =5F

- 12. An object of mass 100 g projected vertically upwards from the ground level has a velocity of 20

ms-1at a height of 10 m. Calculate its initial kinetic

energy at the ground level.

- 10 J B. 20 J
- 30 J D. 50J

[g = 10 ms-2; neglect air resistance]

- An electric water pump rated 1.5 KW, lifts 200kg of

water through a vertical height of 6 metres in 10

seconds. What is the efficiency of the pump?

For what value of Q are the forces in the diagram abovein equilibrium?

- 15o B. 30o
- 45o D. 60o

The figure above shows a block of mass m

sliding down a rough inclined plane QP at angle Q. The forces acting on the block along the

plane QP are

- mg sin Q and the normal reaction
- mg sin Q and the force of friction
- mg cos Q and the normalreaction
- mg cos Q and the force offriction.

A uniform light bean XZ is hinged at X and kept in equilibrium by the forces T and F as shown in the diagram above. If XO = 20 cm and OY = 30cm, express T in terms of F.

- T = 2 3 F

3

- T =2F
- 90.0% B. 85.0%
- 80.0% D. 65.0%

[g = 10ms-2; neglect air resistance]

è **W **

For a rough inclined plane on which lies a body of weight W, the angle è in the diagram above becomes the angle of frictionif

- tan Q = coefficient ofstatic friction
- cos Q = coefficient of dynamic friction C. sin Q = coefficient ofsliding friction D. sec Q = limiting frictional force.
- A load of 20 N on a wire of cross-sectional area 8 x 10-7m-2, produces an extension of 10-4m. Calculate Young’s modulus for thematerial of the wire ifitslength is 3 m.
- 7.0 x 1011Nm-2
- 7.5 x 1011Nm-2
- 8.5 x 1011Nm-2
- 9.0 x 1011 Nm-2
- A cube of sides 0.1 m hangs freely from a string. What is the up thrust on the cube when totally immersed in water?
- 1000N B. 700N
- 110N D. 10N

[Density of water is 1000 kg m-3, g = 10 ms-2]

**719 **

- A piece of wire guaze can be made to lie on water because
- the wire guaze is less dense than water B. the water moleculesrepel the wire guaze upwards.
- the water surface has the effect of an elastic thin skin
- of the cohesive forces between the

water and the wire guaze molecules.

- A liquid of mass 1.0 X 103 kg fills rectangular tank of length 2.5 m and width 2.0 m. If the tank is 4 m high, what isthe pressure at the middle ofthe tank? A. 1.0X 104 Nm-2
- 2.0X 103 Nm-2
- 1.5X 103 Nm-2
- 1.0 X 103 Nm-2(g = 10m/52)
- An empty60 litre petrol tank has a mass of 10 kg. It mass when full offuel of relative density 0.72 is A. 7.2 k B. 33.2 kg
- 43.2 k D. 53.2 kg
- The length of mercury thread when it is at 0oC, 100oC and at an unknown temperature è is 25 mm, 225mm and 174mm respectively.The value ofis A. 85.0oC B. 80.0oC
- 75.0oC D. 70.0oC
- Equal masses of copper and rubber are raised to the same temperature. After sometimes, the copper was observed to be at a lower temperature because A. the specific heat capacity of copper is lower than that ofrubber
- copper expands more than rubber
- the specific heat capacity of rubber is lower than that of copper
- rubber expands more than copper.
- Before starting a journey, the tyre pressure of a car was 3 X 105 Nm-2at 27oC. At the end of the journey, the pressure rose to 4 X 105 Nm-2. Calculate the temperature of the tyre after the journey assuming the volume is constant.
- 400oC B. 300oC
- 273oC D. 127oC
- A mass of a liquid at 300oC is mixed with a mass of the same liquid at 70oC and the temperature of the mixture is 45oC. Find the ratio of the mass of the cold liquid to the mass of the other liquid.
- 3 : 5 B. 5 :3
- 3 : 7 D. 7 :3
- A heating coil rated at 1000 W is used to boil off 0.5 kg of boiling water. The time taken to boil off the water is
- 1.15 X109s B. 1.15 X 107s C. 1.15 X105s D. 1.15 X 103s [Specific latent heat of vaporization of

water = 2.3 X 106J kg-1]

- What happens when a certain quantity of pure ice is completely changed towater at 0oC?
- Latent heat is absorbed, the massremains constant and the volume decreases.
- Latent heat is given out, the massremains constant and the volume decreases.
- Latent heat is given out, the mass increases and the volume remains

constant.

- Latent heat is absorbed, the mass decreases and the volume increases.
- The correct cooling curve for a molten substance such as naphthalene is represented by
- Temp. oC

Time (min)

Temp. oC

Time (min)

Temp. oC

Time (min)

- What happens when a gas expands at a constant temperature?
- It pressure decreases.
- The total momentum of its molecules remains constant.
- Its pressure decreases and the total momentum ofits molecules remains

constant.

- Its pressure decreases and the total

kinetic energy of its molecules

decreases.

**720 **

- Ripples on water and light waves aresimilar because both
- have the same frequency
- can be refracted and diffracted
- are longitudinal waves
- have the same velocity.
- Under constant tension and constant mass per unit length, the note produced by a plucked string is 500 Hz when the length ofthe string is 0.90 m. At 3

Sun

what length is the frequency 150 Hz?

- 3m B. 4m
- 5m D. 6m
- The colours seen in thin films of oil on the road and in soap bubbles are due to
- Reflection B. Interference C. Diffraction D. Polarization.

The diagram above shows two waveforms P and Q at a particular instant of time. The two waves will interfere

- destructively to produce a wave of a larger amplitude
- destructively to produce a wave of a smaller amplitude
- constructively to produce a wave of a larger amplitude
- constructively to produce a wave of a smaller amplitude.
- If the load at the end of a sonometer wire is immersed in a bucket of water, the original fundamental frequency of the wire could be restored by
- decreasing the length of the wire
- increasing the length of the wire
- increasing the mass per unit of the wire D. changing the temperature of the water.
- Moon Earth

X

When the sun, the moon and the earth are as shown in the diagram above, an observer

standing at X is in

- penumbra and sees a partial eclipse
- penumbra and sees a total eclipse
- umbra and seesa partial eclipse
- umbra and sees a total eclipse.
- A boy on looking into a mirror observed that his face appeared to have grown bigger. The boy must have been looking at a
- convex mirror with his face at the focus B. concave mirror with his facebetween the focus and the mirror.
- concave mirror with his face at the

focus

- convex mirror with his face between the focus and themirror.
- Light of velocity 3.0 x 108 ms-1is incident on a material ofrefractive index n. Ifthe velocityoflight isreduced to 2.4 X 108 ms-1in the material, what is n?
- 2.33 B. 2.25
- 1.33 D. 1.25
- A patient with a sight defect has a distance of distinct vision of 150 cm. For him to be able to read a material placed at a distance of 25 cm, what isthe focal length of the glasses he should wear?
- 15.0cm B. 17.6cm
- 21.4cm D. 30.0cm
- The electromagnetic waves that are sensitive to temperature changes are
- X-rays B. gamma-rays
- ultra-violet rays
- infra-red rays.

**721 **

In the diagram above, which of the anglesQ1, Q2, Q , and Q is the angle of deviation of a ray of light 3 4

through the glass prism, XYZ?

- Q3 B. Q2
- Q1 D. Q4
- Which of the figures below showed the correct distribution of charges on an isolated positively charged hollowmetal?

respectively. Find the balance point from the left side of the bridge.

- 20 cm B. 40 cm
- 60 cm D. 80 cm
- Two 50 uF parallel plate capacitors are connected in series. The combined capacitor is then connected across a 100-V battery. The charge on each plate of the capacitor is
- 5.00 X 10-5C B. 2.50 X 10-3C C. 1.25 X 10-3C D. 1.00 X10-2C
- What is the total electrical energy consumed by using an electric cooker rated 1000 W for 5 hrs? A. 5.3 X103J B. 6.5 X 103J C. 1.8 X107J D. 2.3 X 107J

4.6 The power dissipated in an a.c. circuit with an r.m.s. current of 5A, r.m.s. voltage of 10 V and a

**+****+**

**+ ****+ ****+****+ ****+ ****+ ****+ **

**+ ****+ ****+****+ **

**+ +****+**

**+ **

**+ **

**+ **

phase angle of 60ois

- 25 W B. 50 W C. 120 W D. 125 W

**+ **

**+ ****+****+ **

**+****+****+ **47. The voltage of the domestic electric supply is represented by the equation

**D.****+ +**

**+ ****+****+****+****+****+****+****+ **

V = 311 sin 314.2t.

Determine the frequency of the a.c. supply.

**+ **

**+ **

**+ **

**+ **

**+ **

**+ + **

- 50.0 Hz B. 100.0Hz C. 311.0Hz D. 314.2Hz [ = 3.142]
- In a purely inductive circuit, the current

- Three electric cells each of e.m.f. 1.5V and internal resistance 1.0 Ohms are connected in parallel across an external resistance ofT Ohms!. Calculate the value of the current in the resistor.
- 0.5 A B. 0.9 A
- 1.5 A D. 4.5 A
- A galvanometer ofinternal resistance 50 Ohms has a full scale deflection for current of 5 mA. What is the resistance required to convert it to a voltmeter with fullscale deflection of 10V?
- 1 750 Ohms B. 1 950 Ohms C. 2 000 Ohms D. 2 500 Ohms
- If 8 X 10-2J of work is required to move 100 ìC of charge from a point X to a point Y in an electrical circuit, the potential difference between X and Y if
- 4.0 X 102 V B. 4.0 X 104 V C. 8.0 X 102 V D. 8.0 X 104 V
- In a metre bridge experiment, two resistors 2 &! and 3 Ohms occupy the left and right gaps
- lags behind the voltage in phase by 90o B. lead the voltage in phase by 90o
- is in the same phase with the voltage D. leads the voltage by 180o.
- One of the features of the fission process is that A. Its products are not radioactive
- It leads to chain reaction
- Neutrons are not released
- The sum of the masses of the reactants equals the sum of the masses of the

products.

- The graphite rods surrounding the uranium fuel rods in a nuclear reactor, are used to
- Absorb the neutrons and hence halt the nuclear process
- Create the neutrons and hence start up the nuclear process.
- Slow down the neutrons and hence sloe\w the nuclear process.
- Speed up the neutrons and hence speed up the nuclear process.

**722 **

Physics 1998

- The physical quantity that has the same dimensions as impulseis
- Energy B. Momentum C. Surface tension D. Pressure.
- A ball is moving at 18ms-1in a direction inclined at 600to the horizontal. The horizontal

component of its velocity is

9 3ms-1

- B. 6 3ms-1 C. D. 9ms-1

6 3ms-1

A body on the ground is acted on by a force of 10N at a point P as shown in the diagram above. What force is needed to stop the bodyfrom moving eastward?

- 5N in the direction of East
- 5N in the direction ofWest
- 5″3N in the direction ofWest.
- 10N in the Southwestdirection.
- In free fall, a bodyof mass 1kg dropsfrom a height of125m fromrest in 5s. Howlong will it take another body of mass 2kg to fall from rest from the same height?
- In an experiment, a constant force is applied to several masses (m) and the corresponding accelerations (a) are measured. Which of the following graphs correctly represents the experiment?
- III and IV only
- II and IVonly
- I and IIIonly
- I and IIonly
- A uniform metre rule weighting 0.5N isto be pivoted on a knife-edge at the 30cm-mark. Where will a force of 2N be placed from the pivot to balance the metre rule?
- 95cm B. 25cm
- 20cm D. 5cm
- A bullet fired at a wooden block ofthickness 0.15m manages to penetrate the block. If the mass of the bullet is 0.025kg and the average resisting force of the wood is 7.5 x 103N, calculate the speed of the bullet just before it hits the wooden block.
- 450ms-1 B. 400ms-1
- 300ms-1 D. 250ms-1
- A man whose mass is 80kg climbs a staircase in 20s and expends a power of 120W. Find the height of the staircase.
- 55 B. 105 A. 1.8m B. 2.0m C. 125 D. 155 C. 2.5m D. 3.0m (g = 10ms-2)

[g = 10ms-2]

- A ball of mass 0.15kg is kicked against a rigid vertical wall with a horizontal velocity of 50ms-1, calculate the impulse ofthe ball on the wall.
- 3.0Ns B. 4.5Ns
- 7.5Ns D. 12.0Ns
- The force of attraction between two point masses is 10-4N when the distance between them is 0.18m. If the distance is reduced to 0.06m, calculate the force.
- 1.1 x 10-5N B. 3.3 x 10-5N C. 3.0 x 10-4N D. 9.0 x 10-4N
- A parachute attains a terminal velocity when A. Its density is equal to the density of air B. The viscous force of the air and the upthrust completely counteract its

weight.

- It expands as a result of reduced external pressure
- The viscous force of the is equal to the sum of the weight and upthrust.

**723 **

- In a wheel and axle mechanism, the diameters of the wheel and axle are 40cm and 8cm respectively. Given that the machine is 80% efficient, what effort isrequired to lift a load of 100N?
- 20N B. 25N
- 50N D. 80N
- The tendon in a man’sleg is 0.01m long. If a force of 5N stretches the tendon by 2.0 x 10-5m, calculate the strain on the muscle.
- 5×106 B. 5×102
- 2 x 10-3 D. 2 x 10-7
- Which of these statements are correct for the pressures in liquids?

I Pressure in a liquid at a point acts equally in all directions

II Pressure increases with depth

III Pressure at a depth depends on the shape of the container.

IV Pressures at the same depth in different liquids are proportional to the densities

of the liquids.

- I, II and IIIonly
- I, II and IVonly
- I, III and Iv only
- II, III and IVonly.
- The atmospheric pressure due to water is 1.3 x 106 Nm-2. What is the total pressure at the bottom of an ocean 10m deep?
- 1.3x 107Nm-2 B. 1.4x 106Nm-2 C. 1.4x 105Nm-2 D. 1.0x 105Nm-2
- A solid of weight 0.600N istotally immersed in oil and water respectively. If the upthrust in oil is 0.210N and the relative density of oil is 0.875 find the upthrust in water.
- 0.6000N B. 0.360N
- 0.240N D. 0.180N
- A platinum resistance thermometer records 3.0Ù at 00C and 8.0 Ù at 1000C. If it records 6.0Ù in a certain environment, the temperature of the medium is
- 800C B. 600C
- 500C D. 300C
- The linear expansivity of brass is 2 x 10-5C-1. If the volume of a piece of brassis 15.00 cm3at 00C, what isthe volume at 1000C?
- 16.03cm3 B. 16.00cm3 C. 15.09cm3 D. 15.03cm3

attained, calculate T.

- 330C B. 600C
- 870C D. 1140C
- A 500W heater is used to heat 0.6kg of water from 250C to 1000C in t seconds. If another 1000W heater 1

is used to heat 0.2kg ofwater from 100C to 1000C in t2 seconds, find t1 .t2

- 50 B. 5
- 5/ D. 1/

4 5

- How many grams of water at 170C must be added to 42g ofice at 00C to melt the ice completely? A. 200g B. 300g
- 320g D. 400g

[Specific latent heat of fusion of ice = 3.4 x 105Jkg-1, Specific heat capacity of water = 4200 Jkg-1K-1]

- A vapour is said to be saturated when
- More molecules return to the liquid than the amount that left it.
- A dynamic equilibrium exist between the molecules of the liquid and the vapour

molecules at a giventemperature.

- The vapour pressure is equal to the atmospheric pressure
- All molecules are moving with the same speed in all directions at a given

temperature.

- One valid assumption ofthe kineic theory of gases is that
- the molecules of a gas are constantly in state of motion and the number of collisionsremain constant.
- The number ofmolecules of gas increases with increasing pressure
- As the temperature increases, the number of collisions made by the gas molecules remain constant.
- The molecules of gas are all identical and are very small insize.
- The physical properties of sound waves can best be described by
- Reflection and diffraction
- Polarization and reflection
- Polarization and diffraction
- Polarization and refraction
- The velocity of a sound wave at 270C is 360ms-1. Its velocity at 1270C is

120 3ms-1

- B.

240 3ms-1

- A gas has a volume of100cm3at 270C. Ifit is heated C. D. to temperature T until a final volume of 120cm3is

240ms-1 720 3ms-1

**724 **

- In a closed organ pipe producing a musical note, an antinode will always be produced at
- The closed end
- The open end
- The middle
- All the parts of the pipe.
- A steel wire of length 0.50m is stretched between two fixed points and its fundamental frequency is 200Hz. The speed ofthe wave in the wire is
- 100ms-1 B. 120ms-1
- 200ms-1 D. 250ms-1
- In a resonance tube experiment, if the fundamental frequencyofthe vibrating air column is 280Hz, the frequency of the third overtones is
- 70Hz B. 840Hz
- 1120Hz D. 1960Hz
- An object O lies at a distance m in front of a concave mirror of the focal length f. If m<f, then the final image obtained will be
- Virtual and diminished
- Magnified and erect
- Real and inverted
- Diminished and erect.
- An object is placed in front of two plane mirrors inclined at an angle è0. Ifthe total number ofimages formed is 7, find the value of è?
- 300 B. 450
- 510 D. 900
- The most suitable type of mirror used for the construction of a searchlight is the
- Concavemirror
- Convexmirror
- Spherical mirror
- Parabolic mirror.
- The displacement d produced in a glass block of thickness t and refractive index n when an object is viewed through it is
- t – n B. t(1 + 1/ )

n

- t(1 –1/ ) D. t(1/ –1)

n n

- The correct shape of the graph of uv against (u + v) for an object distance u and image distance v in n experiment to find the focal length of a convex lens is given as
- A man wears convex lens glasses of focal length 30cm in order to correct hiseye defect. Instead of the optimum 25cm, his least distance of distinct vision is
- 14cm B. 28cm
- 75cm D. 150cm
- Which of the following are true about infra-red radiation?

I It isinvisible

II It is called heatray

III Its frequency is higher than that ofblues light

IV It travels as a transverse wave.

- I, II,III and IV.
- I, II and Ivonly
- I, III and IVonly.
- II, III and IVonly.
- The force of repulsion between two pointpositive charges 5uC and 8uC separated at a distance of 0.02m apartis
- 1.8 x 10-10N B. 9.0 x 10-8N C. 9.0x 102N D. 4.5x 103N
- An ebonite rod rubbed with fur attracts a glass rod rubbed with silk because
- Ebonite has a negative charge while glass has a positive charge
- Ebonite has a positive charge while glass has a negative charge
- Both have negative charges
- Both have positive charges.
- Which of the following diagrams show the correction ofthe magnetic lines offorce of a vertical wire XY carrying a current I?
- Which ofthe following can be used to reduce local action in a Leclanche cell?
- A carbon rod as the positive pole.
- Pure zinc as the negative pole.
- Potassium permanganate solution in contact with the positive pole.
- Common salt solution.

**725 **

The total resistance measured at PQ in the diagram above is

- 18.0Ohms B. 11.0 Ohms C. 4.0 Ohms D. 2.0 Ohms
- Find the work done in moving a 2C charges between two points X and Y in an electric field if the potential difference is 100 volts.
- 50J B. 100J
- 200J D. 400J
- A parallel capacitor has a common plate area of 5 x 10-8m-2and plate separation of 2 x 103m. Assuming free space, what is the capacitance?
- 2.25 x10-17F
- 4.50 x10-17F
- 2.25 x10-16F
- 4.50 x10-16F
- The iron core of an induction coil is made from bundles of wires so as to
- Minimize eddy-currents
- Generate eddy-currents
- Prevent sparking at the contact breaker D. Get the greatest possible secondary voltage.
- Electricity is supplied to a school along a cable of total resistance 0.5 Ù with the maximum current drawn fromthe mains as 100A. the maximumenergy dissipated as heat for 1hr is
- 3.6 x 103J B. 5.0 x 103J C. 3.0 x 105J D. 1.8 x 107J
- 5000ðHz
- 2500ðHz
- 5000/ðHz
- 2500/ðHz
- A transformer which can produce 8V from a 240V a.c. supply, has an efficiency of 80%. If the current in the secondary coil is 15A, calculate the current in the primarycoil.
- 0.625A B. 1.600A
- 2.500A D. 6.250A
- The electrochemical equivalent ofmetal is 1.3 x 10– 7kgC-1. The mass of the metal which 2.0 x 104Cof electricity will deposit from a suitable electrolyte is
- 6.5x 10-2kg B. 2.6 x 10-2kg C. 6.5x 10-3kg D. 2.6x 10-3kg
- A radioactive substance has a half-life of 80 days. Ifthe initial number of atoms in the sample is 6.0 x 1010, how many atoms would remain at the end of 320 days?
- 3.75x 109 B. 7.50x 109 C. 3.00 x 1010 D. 5.63 x1010
- In a nuclear fusion experiment, the loss of mass amounts to 1.0 x 10-6kg. The amount of energy obtained from the fusion is
- 3.0x 10-4J
- 3.0x 10-1J
- 9.0 x104J
- 9.0 x1010J

[Speed of light = 3.0 x 108ms-1]

- In photoelectric effect, electrons will leave the metal surface when illuminated by light of appropriate frequency if the photon energy is A. Greater than the workfunction.
- Less than the work function
- Equal to the workfunction
- Equal to the maximum kinetic energy of

In the a.c. circuit diagram above, the resonance frequency is

the electrons.

**726 **

Physics 1999

- A car of mass 800kg attains a speed of 25ms-1in 20 seconds. The power developed in the energy is A. 1.25 x 104 W B. 2.50 x 104W C. 1.25 x 106 W D. 2.50 x 106 W
- A lead bullet ofmass 0.05kg is fired with a velocity of 200ms-1into a lead block ofmass 0.95 kg. Given that the lead block can move freely, the final kinetic energy after impactis
- 50 J B. 100 J
- 150 J D. 200 J
- A ball of mass 0.1kg is thrown vertically upwards with a speed of 10 ms-1from the top of a tower 10m high. Neglecting air resistance, itstotal energy just before hitting the ground is
- 5 J B. 10 J
- 15 J D. 20 J

[g = 10ms-2].

- The figure above represents a frictionless pulley system in which a weight W is in equilibrium with a weight of 40N. Find the value of W
- 13.1N B. 20.0N
- 40.0N D. 80.0N
- The diagram above shows a solid figure with base PQ and centre gravity G on an inclined plane. Which of the following statements is correct? A. The solid will fall over if the vertical line through G lies outside the base.
- The solid will fall over if the vertical line through G lines inside thebase.
- The solid will not fall over if thevertical line through G lies outside thebase.
- The solid can never fallover.
- Two bodies have masse in the ratio 3 : 1. They experience forces which impart to them accelerations in the ratio 2: 9 respectively. Find the ratio of the forces themasses experience.
- 1 :4
- 2 :1
- 2 :3
- 2 : 5.

The diagram above shows the velocity-timegraph of a vehicle. Its acceleration and retardation respectively are

- 8.0 ms-2, 4.0ms-2,
- 4.0 ms-2, 8.0ms-2,
- 4.0 ms-2, 2.0ms-2,
- 2.0 ms-2, 4.0 ms-2
- A particle of mass 10-2kg is fixed to the tip of a fan blade which rotates with angular velocity of 100 rad s-1. If the radius of the blade is 0.2m, the centripetal force is
- 2 N B. 20 N
- 200N D. 400N
- The inner diameter of a small test tube can be measured accurately using a
- Micrometer screw guage
- Pair ofdividers
- Metre rule
- Pair of vernier calipers.
- A gas at a volume V0in a container at pressure P0, is compressed to one fifth of its volume. What will be its pressure if it maintains its original temperature T?
- Po/5
- 4/5 P0
- P0
- 5P0
- A piece ofsubstance of specific heat capacity 450 J kg-1 K-1falls through a vertical distance of 20m from rest. Calculate the rise in temperature ofthe

**727 **

substance on hitting the ground when all its

energies are converted into heat.

- 2/90C B. 4/90C
- 9/40C D. 9/20C

[g = 10ms-2].

The diagram above shows a lift pump with valves at P and Q. during a downward stroke ofthe piston, A. Both valves are open

- P is open while Q is closed
- P is closed while Q isopen
- Both valves are closed.

In the J – tube above, Y and X are on the same horizontal level and 30cm3 of air is trapped above Y when the atmospheric pressure is 75cm Hg. Calculate the volume of air trapped above Y when 15cm Hg is now poured into the limb aboveX.

- 15cm3 B. 25cm3
- 35cm3 D. 45cm3
- I. A liquid boils when its saturated vapour pressure is equal to the external

pressure.

- Dissolved substances in pure water lead to increase in theboiling point.

III. When the external pressure is increased, the boiling point increases.

IV Dissolved substances in pure water decrease the boiling point.

Which combination of the above are peculiarities of the boiling point of a liquid?

- I, II andIII
- I, II,III and IV
- I, II andIV
- II, III andIV.
- When the temperature of a liquid is increased, its surface tension
- Decreases B. Increases C. Remains constant
- Increase then decreases.
- When the brakesin a car are applied, the frictional force on the tyres is
- A disadvantage because it is in the direction of motion of the car
- A disadvantage because it is in the opposite direction of motion of the car.
- An advantage because it is in the direction of motion of the car.
- An advantage because it is in the opposite direction of motion of the car.
- The lowest note emitted by a stretched string has a frequency of 400Hz. How many overtones are their between 40Hz and 180 Hz?
- 4 B. 3
- 2 D. 1
- A man stands 4m in front of a plane mirror. If the mirror is moved 1m towards the man, the distance between him and hisimage is
- 3m B. 5m
- If the stress on a wire is 107 Nm-2and the wire is stretched fromits original length of 10.00cm to 10.05 cm. The young’s modulus of the wireis
- 5.0x 104Nm-2 B. 5.0x 105Nm-2 C. 2.0x 108Nm-2 D. 2.0x 109Nm-2
- A solid weights 10.0N in air, 6.0 N when fully immersed in water and 7.0 N when fully immersed in a certain liquid X. Calculate the relative density of the liquid.
- 5/3 B. 4/3
- ¾ D. 7/10
- 6m D. 10m
- If a sound wave gors from a cold-air region to a hot-air region, its wavelength
- Increase
- Decrease
- Decrease then increase
- Remain constant
- The inside portion ofpart of a hollowmetalsphere of diameter 20cmis polished. The portion will

**728 **

therefore forma

- Concave mirror offocal length 5 cm
- Concave mirror offocal length 5 cm
- Convex mirror offocal length 5 cm
- Convexmirror offocal length 20cm.
- The equation of a wave traveling along the positive x-direction is given by y = 0.25 x 10-3sin (500 t – 0.025 x). Determine the angular frequency of the wave motion,
- 0.25 x 10-3rad s-1
- 0.25 x 10-1rad s-1
- 5.00 x 102rads-1
- 2.50 x 102rads-1
- Calculate the mass of ice that would melt when 2kg of copper is quickly transferred from boiling water to a block of ice without heat loss
- 8/33kg B. 33/80kg
- 80/33kg D. 33/8kg

[Specific heat capacity of copper = 400 J kg-1 K-1; Latent heat of fussion of ice = 3.3 x 105J kg-1]

The diagram above represents a transverse electromagnetic wave traveling with speed 3.0 x 108ms-1. What is the frequency of the wave?

- 3.0x 107Hz
- 90x 107Hz
- 1.0 x 109Hz
- 3.0 x 109Hz
- The temperature gradient across a copper rod of thickness 0.02m, maintained a two temperature junctions of 200C and 800C respectively is
- 3.0 x102Km-1 B. 3.0 x 103Km-1 C. 5.0 x103Km-1 D. 3.0x 104Km-1

The diagram above showa magnet X with its South pole moved along a soft-iron bar PQ in the direction

shown. After some time, the poles at P and Q respectively are

- North – North
- North – South
- South – North
- South – South
- Four cells each of e.m.f. 1.5 V and internal resistance of 4 Ohms are connected in parallel. What is the effective e.m.f. and internal resistance of the combination?
- 6.0V, 16Ohms
- 6.0V, 1Ohms
- 1.5V, 4Ohms
- 1.5V, 1Ohms

In the circuit above, the ammeter reads a current of 5.0 A when R = 8 Ohms and reads 7.0 A when R= 5 Ohms. The value ofthe unknown resistance X is

- 10.0Ohms B. 7.5 Ohms C. 5.0 Ohms D. 2.5 Ohms
- An astronomical telescope is said to be in normal adjustment when the
- Eye is accommodated
- Focal length of objective lens is longer than that of eye piece
- Final image is at the near point of eye D. Final image is at infinity.
- Steel is more suitable for permanent magnet than iron because the former
- Is easily demagnetized byshaking vigorously B. Is an alloy of many metals
- Is easily magnetized by alternating current through one cycle
- Retains magnetism more than iron.

**729 **

The diagram above shows the prism arrangement

in a

- Binocular B. Spectrometer
- Penscope D. Projector
- The velocities offlight air and glass are 3.0 x 108ms and 2.0 x 108ms-1respectively. If the angle of

refraction is 300, the sine of the angle of incidence

is

In the circuit above, the potential across each capacitor is 100V. The total energy stored in the two capacitors is

- 3.0 x104J B. 3.0 x 102J C. 2.5x 10-2J D. 6.0 x 10-3J

- 0.33 B. 0.50 C. 0.67 D. 0.75

In the series a.c. circuit shown above, the p.d acrossthe inductor is 8Vr.m.s. The effective voltage is

- At what frequency would a 10 H inductor have a reactance of 2000 ohms?
- ð/200Hz B. ð/ 100Hz
- 100/ Hz D. 100ðHz

ð

- A 3000 W electric cooker is to be used on a 200V mains circuit. Which of the fuses below can be used safely with the cooker?
- 2A B. 5A
- 10A D. 20A
- A galvanometer has a resistance of 5 Ù. Byusing a shunt wire of resistance 0.05 Ù, the galvanometer could be converted to an ammeter capable of reading 2 A. What is the current through the

galvanometer?

- 2V B. 10V A. 2 mA B. 10 mA C. 14V D. 48V C. 20 mA D. 25 mA

- The core of an efficient transfoemer should consist oflaminated pieces of metal in order to
- Increase the heat produced by increasing the eddy current
- Increase the heat produced by reducing the eddy current
- Reduce the heat produced by increasing the eddy current
- Reduce the heat produced by reducing the eddy current.
- In Fleming’s right-hand rule, the thumb, the forefinger and the middle finger if held mutually at right angles represent respectively, the
- Motion, the field and induced current
- Induced current, the motion and the field C. Fireld, the induced current and the motion D. Induced current, the field and the motion.

In the diagram above, if the internal resistance of the cell is zero, the ratio of the power P1 and P2 dissipated by R1 and R2 respectively, is

- R2

R1

- R1

R2

- R1 + R2

R1

- R1 + R2

R2

**730 **

- If x is the uncertainty in the measurement of the position of a particle along the x-axis and “Px is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is givenas
- x Px >h
- x Px = 0
- x Px < h
- x Px =00
- Na + Proton X + alpha particle. What are the values of p and q respectively in the equation above?
- 10 and 20 B. 12 and 24 C. 20 and 10 D. 24 and 12.
- A semi-conductor diode is used in rectifying alternating current into direct current mainly because it
- Allows current to flowin either direction B. Is non-linear
- Offers a high input resistance
- Allows current to flow only in one direction.
- In semi-conductors, the carriers of current at room temperature are
- Electrons only
- Electrons and holes
- Holes only
- Electrons and ions
- What is the speed of a particle of mass 10-27kg whose wavelength is 10-8m?
- 6.63 ms-1 B. 66.30 ms-1 C. 663.00 ms-1 D. 6630.00 ms-1

(h = 6.63 x 10-34 JS)

- In a series R-L-C circuit at resonance, the voltages across the resistor and the inductor are 30 V and 40 V respectively. What is the voltage across the capacitor?
- 30V B. 40V
- 50V D. 70V
- Gamma rays are produced when
- High velocity electrons are abruptly stopped in metals
- Energy changes occur within the nucleus atoms
- Energy changes occur within the electronic structure of atoms
- Electrons are deflected in very strong magnetic fields.
- In the Rutherford scattering experiment, a beamof alpha particles was fired at a thin gold film with some of the particles being considerably deflected. This shows that
- A gold nucleus contains protons, nuietrons and electrons uniformly distributed in a tiny volume.
- The gold nucleus is positively charged andis concentrated in a tiny volume
- The gold nucleus emitted alphaparticles D. The gold nucleus is concentrated in a tiny volume and contains alpha particles.

Physics 2000

- A catapult used to hold a stone of mass 500gis 3. I. The frictional force is extended by 20cm with an applied force f. If the independent of the area of the surfaces stone leaves with a velocity of 40 ms-1, the value in contact,

of F is II The frictional force depends on the A. 4.0 x104N B. 4.0 x 103N nature of the surfaces in contact C. 2.0 x103N D. 4.0 x 102N III The frictional force depends on the speed sliding

- A hand bag containing some load weighting 162N is carried by two students each holding the handle ofthe bag next to him. If each handle is pulled at 60 to the vertical, find the force on each student’s

IV The frictional force is directly proportional to the normal reaction

Which combination of the above is true of sliding friction?

arm

- 324 N B. 162 N C. 121 N D. 81 N
- C.

I, II and IV I, III and IV

- D.

I, II and III II, III and IV.

**731 **

- When a ship sails from salt water into fresh water, the friction of its volume above the water surface will
- Remain the same
- Increase
- Decrease
- Increase then decrease.
- A simple pendulum has a period of 17.0s. When the length is shortened by 1.5m, its period is 8.5s. Calculate the original length of the pendulum. A. 1.5m B. 2.0m
- 3.0m D. 3.0m
- At a fixed point belowa liquid surface, the pressure downward is P1 and the pressure upward is P2. It can be deduced that
- A stream isflowing at 0.75ms-1and at boat heading perpendicular for the stream landed at the opposite bank at an angle 300. Calculate the velocity of the boat.
- 0.65ms-1 B. 0.86ms-1 C. 1.00ms-1 D. 1.50ms-1
- I. Coherence

II Same frequency

III Same wavelength

IV Same intensity.

Which of the conditions above are necessary to produce interference fringes?

- I, II and III B. I, II andIII C. I, II and IV D. II andIII.
- An engineer intends to deviate a light ray from its

- P = P B. P > P path 1200through reflection from plane mirror.

1 2 1 2

- P1< P2 D. P1 > P2
- I. Its velocity is constant

II No work is done on the body

III It has constant acceleration away from

the center

IV The centripetal force is directed towards the center.

Which combination of the above is true of a body moving with constant speed in a circular track?

- I and III B. I andIV
- II and III D. II and IV
- The velocity
*v*of a particle in a time*t*is given by the equation*v*= 10+2*t*2. Find the instantaneous acceleration after 5 seconds. - 10 ms-2 B. 15 ms-2
- 20 ms-2 D. 60 ms-2
- If the force and the velocity on a system are each

Calculate the angle of incidence.

- 200 B. 300 C. 400 D. 600

Days 1 Day 2 Day 3

Dry 300C 290C 250C Wet 220C 220C 210C

The readings above are for three consecutive days from a wet and dry bulb hygrometer. It can be concluded that the relative humidity for the three days

- Increased ssteadily
- Remained unchanged
- Was least on day 1
- Decrease steadily

reduced simultaneously by half, the power of the system is

- Doubled B. Constant C. Reduced to a quarter
- Reduced by half.
- The velocity ratio of a machine is 5 its efficiency is 75%. What effort would be needed to lift a load of 150N with the machine?
- 50N B. 40N
- 30N D. 20N
- A rope is being used to pull a mass of 10kg verticallyupward. Determine the tension in the rope if, starting from resr, the mass acquires a velocity of 4ms-1in8.
- 105 N B. 95 N
- 50 N D. 5 N
- Total internal reflection occurs when light moves from
- Air to water
- Water to glass
- A dense medium to a less dense medium D. A less dense medium to a dense medium
- One end of a long wire is fixed while vibrator is attached to the other end. When the vibrator is energized, the types of waves generated in the wire are
- Stationary and transverse
- Progressive
- Stationary and longitudinal
- Progressive and longitudinal.

**732 **

- A sonometer wire is vibrating at frequency
*f*0. If the tension in the wire is doubled while the length and the mass per unit length are kept constant, the new frequency of vibration is *f**0*

*2 *

*2 f**0**f**0**2**f**0**2*- A boy observes a piece of stone at the bottom of a river 6.0m deep. If he looksfrom the surface ofthe river, what is the apparent distance of the stone fromhim.
- 4.5m B. 5.0m
- 5.5m D. 8.0m
- A metal of mass 0.5kg is heated to 1000C and then transferred to a well-lagged calorimeter of heat capacity 80J K-1containing water of heat capacity 420JK-1at 150C. If the final steady temperature of the mixture is 250C, find the specific heat capacity of the metal
- 92 J kg –1 K-1 B. 133 J kg –1 K-1 C. 286 J kg –1 K-1 D. 887 J kg –1 K-1
- Thediagram aboveshowsa maximum andminimum thermometer divided into three portions P, Q and R. Which of the following is true about the

respective contents of P, Q and R?

- Alcohol, mercury andalcohol
- Air, alcohol andmercury
- Mercury, alcohol and mercury
- Air, mercury andalcohol.
- The main reason for making the cover of a vacuum flask airtight is to prevent heat loss by
- Conduction B. Evaporation C. Radiation D. Convection
- A travelling wave moving from left to right has an amplitude of 0.15m, a frequency of 550Hz and a wavelength of 0.01m. The equation describing the wave is
- y= 0.15 8In 200 ð (x – 5.5t)
- y= 0.15 8In ð (0.01x – 5.5t)
- y= 0.15 8In 5.5 ð (x – 200t)
- y= 0.15 8Inð (550 x – 0.01t)
- A transverse wave is applied to a string whose mass per unit is 3 x 10-2kgm-1. If the string is under a tension of 12N, the speed of propagation of the wave is
- 40ms-1 B. 30ms-1
- 20ms-1 D. 5ms-1
- Aquantity of water at 00C heated to about 300C. At each degree rise in temperature, its density will A. Rise steadily B. Rise then fall C. Fall steadily D. Fall then rise.
- A thin wire with heavy weights attached to both ends is hung over a block of ice resting on two supports. If the wire cuts through the ice block while the block remains solid behind the wire, the process is called
- Fusion B. Sublimation C. Condensation D. Regelation
- A cell of internal resistance 0.01 ohms can be measured accurately using the
- Ohm-meter
- Potentiometer
- Electroscope
- Metre bridge
- An electron of charge 1.6 x 10-19C and mass 9.1 x 10-31kg is accelerated between two metal plates with a velocity of 4 x 107ms-1, the potential difference between the plates is
- 4.55x 101V B. 9.10 x 101V C. 4.55x 102V D. 4.55 x103V

In the diagram above, a beam of white light travels from a rare to dense medium. What colours oflight do the rays a, b, c respectively represent.

- Blue, yellow andred
- Green, red andblue
- Red, green and blue
- Yellow, blue andred.

**733 **

The diagram above shows two capacitors P and Q of capacitances 5uF and 10 uF. Find the charges stores in P and Q respectively.

- 200 uCand 100 uC
- 100 uCand 200 uC
- 4 uC and 2uC
- 2 uC and 4uC
- What optical instrument can best be constructed with converging lenses of focal lengths 500cm and 5cm?
- Compound microscope
- Terrestrial telescope
- Astronomical telescope
- Galileo’s telescope
- A projector lantern is used to give the image of a slide on a screen. If the image is 24 times as large as the slide and the screen is 72.0m from the projecting lens, what is the position of the slide from the lens?
- 4.0m B. 3.5m
- 3.0m D. 0.3m
- A radio is operated by eight cells each of e.m.f. 2.0V connected in series. if two of the cells are wrongly connected, the net e.m.f. of the radio is A. 16V B. 12V
- 10V D. 8V
- A 2H inductor has negligible resistance and is connected to a 50/ Hz a.c. supply. The reactance of the inductor is
- 200Ohms
- 50 Ohms
- 100Ohms
- 25 Ohms
- Ifthe fraction ofthe atoms of a radioactivematerial

left after 120 years is 1/

What is the half-life of the

- If a charged ion goes through combined electric and magnetic fields, the resultant emergent velocity of the ion is
- E

B

- EB

material?

- 2 years B. 10 years C. 20 years D. 24 years

64

- B

E

- E –B

In the diagram above, the values of V1and V2are respectively

- 1V and 1 V3
- 1 V and 1V

3

- A certain readioactive source emits radiations that were found to be deflected by both magnetic and electric fields. The radiations are
- x-rays
- beta rays
- gamma rays
- ultra-violet rays
- In a pure semicondctor, the number of electronin the conduction band is
- Equal to the number of holes in the valence band
- Greater than the number of holes in the valence band
- Less than the number of holes in the valence band
- Twice the number of holes in the valence band.
- A cell of internal resistance 1 ohms supplies current to an external resistor of 3 ohms . The efficiency of the cell is

- 1 V and 2 V A. 75% B. 50%

3 3 1V and 2 V

3

- 33% D. 25%

**734 **