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SECTION A – Multiple-choice Questions – Answer ALL Questions
SECTION B – Answer Any THREE Questions
The multiple choice answer sheet for Section A and the answer book for Section B
must be handed in separately at the end of the examination.
INSTRUCTION FOR SECTION A
1. ANSWER ALL QUESTIONS. You should mark all your answers on the Answer
Sheet.
2. All questions carry equal marks.
3. You should mark only ONE answer for each question. If you mark more than one
answer, you will receive NO MARKS for that questions.
4. No marks will be deducted for wrong answers.
5. Where necessary, take g to be 10ms-2 and take c to be 3x108ms-1.
1. Which of the following pairs of quantities of a moving object must be in the same
direction?
(1) acceleration and change in momentum
(2) displacement and velocity
(3) velocity and acceleration
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
2. A 100m long train traveling at 30m/s is passing a 200m long train traveling on a
parallel track at 10m/s in the same direction. A passenger in the first train is seeing
the 200m train for a period of
A. 5s
B. 10s
C. 20s
D. 30s
3. A stone thrown upward is hitting the ground with the speed of 20m/s. The
maximal height reached by the stone was (ignore air resistance)
A. 10m
B. 20m
C. 40m
D. cannot be determined
4. A man stands on an open truck which can run on frictionless horizontal rails as
shown. The man and the truck are at rest. The man now walks to the other end of
the truck and stops.
(1) The truck continues to move to the right after the man ceases to walk along it.
(2) The center of mass of the (man plus truck) remains at rest throughout the
man’s walk.
(3) The kinetic energy of the man is at all times equal to that of the truck during
the man’s walk.
(4) The push of the man on the truck is equal in size to the push of the truck on the
man at all times during the man’s walk.
A. 1,2 and 3 only
B. 1 and 3 only
C. 2 and 4 only
D. 4 only
5. A model rocket accelerates upwards from rest on the ground at 50 m/s2 for 2.0 s
before it’s engine burns out. The rocket then coasts upward. What is the maximum
height that the rocket reaches? You may assume air resistance is negligible.
A. 100m
B. 500m
C. 600m
D. 1000m
6. You want to hit a small box on the floor with a marble fired from a spring-loaded
gun that is mounted on a table. The target box is a distance R horizontally from
the edge of the table; see the figure below. You compress the spring a distance d,
but the center of the marble falls short by a distance r of the center of the box.
How far should you compress the spring to score a direct hit (neglect friction)?
d2
Rr
d (R  r)
B.
R
A.
d2
Rr
Rd
D.
Rr
C.
7. A trolley, T, can run on a frictionless table. Two much smaller but equal masses, P
and Q, are hung by strings which pass over frictionless pulleys shown. The string
is of such a length that when T is in equilibrium, P and Q both just touch the
ground. T is pulled to one side and released. A graph of the velocity, v, of the
trolley against time, t, would look like.
8. If the value of gravitational acceleration at a height h above the Earth’s surface is
the same as that at a depth d below the Earth’s surface (with both h and d small
compared to the Earth’s radius R), then
A. h  d
B. h  d / 2
C. h  d 2 / R
D. h  2d
9. Two satellites of masses M1 and M2 have escape velocities V1 and V2 from the
surface of a planet of radius R with acceleration due to gravity g. Which of the
following is true?
A. V1  V2
B. V1 / V2  (M 2 / M 1 ) 2
C. V1 / V2  M 2 / M 1
D. V1 / V2  M 1 / M 2
10. An Earth satellite is moved from one stable circular orbit to another stable circular
orbit at a greater distance from the Earth. Which of the following quantities
increases for the satellites as a result of the change?
A. Gravitational force
B. Linear speed in the orbit
C. Angular velocity
D. Gravitational potential energy
11. The figure shows the elliptical orbit of a planet with the Sun at the focus. The
areas of regions 1 and 2 are the same. If the planet takes time t1 to go from one
end to the other end of region 1 and t2 to go from one end to the other end of
region 2, then what is the relationship between t1 and t2?
A. t1  t 2
B. t1  t 2
C. t1  t 2
D. Cannot be determined
12. The period of a simple pendulum undergoing simple harmonic motion may be
increased by
A. using a heavier pendulum bob
B. increasing the amplitude of oscillation.
C. placing the pendulum at the top of a mountain.
D. shortening the string attached to the bob.
13. A body performs simple harmonic motion along the straight line MNOPQ.
Its kinetic energy at N, and at P, is one half of its peak value at O. If the period of
oscillation is T then the time taken to travel from n to p directly, along NOP is
A.
1
T
2
B.
1
T
4
C.
D.
T
2 2
1
T
8
14. Which graph best represents the relationship between image size (Si) and mage
distance (di) for real images formed by a converging lens?
15. An ideal gas is heated at constant volume until its pressure doubles. Which one of
the following statements is correct?
A. The mean speed of the molecules doubles.
B. The number of molecules doubles.
C. The mean square speed of the molecules doubles.
D. The r.m.s speed of the molecules doubles.
16. Heat is supplied to a gas in a container which is maintained at a constant volume.
Which of the following statements is/are correct?
(1) The average separations of the gas molecules increases
(2) The mean square speed of the gas molecules increases.
(3) The rate of collision of the gas molecules with the container walls
increases.
A. 1 only
B. 3 only.
C. 1 and 2 only.
D. 2 and 3 only.
17. The graph shows the behavior of a length of steel wire in the region for which the
wire obeys Hooke’s law. The graph is part of parabola. The variable x and y might
represents
A. x = stored elastic energy; y = tension
B. x = stress; y = strain
C. x = strain; y = stress
D. x = strain; y = actual length of the wire
18. A force of 120N extends 2.0m of steel wire by 3.0 mm, while a force of 80N
extends 2.5m of brass wire, whose diameter is twice that of the steel wire by
1.0mm. If both wires obey Hooke’s law, the ratio of Young’s modulus for steel to
that for brass is
A. 2:5
B. 3:5
C. 4:5
D. 8:5
19. Consider an experiment where monochromatic light is incident perpendicularly
from air on a thin, flat film of material that has an index of refraction n=1.2. the
thickness of the film is the minimum required for there to be constructive
interference between the light that is reflected from the two surfaces of the film.
If the air in this experiment were replaced by water, with an index of refraction
n=1.33, then which of the following statements is true?
A. There would no longer be constructive interference because the wavelength of
light is smaller than that in air.
B. The addition of water will induce a phase shift of the reflected light which will
cause there to be destructive interference.
C. Light will no longer be reflected by the thin film and thus no form of
interference will be observed.
D. There will still be constructive interference between the light that is reflected
from the two surfaces of the film.
20. An unpolarized microwave travels along the positive y-axis. A metal grid is placed
in the xz-plane. The electromagnetic wave detected by the detector is
A. of zero intensity
B. unpolarized.
C. plane-polarized in the xz-plane.
D. plane-polarized in the xy-plane.
21. A beam of white light is shone normally on a diffraction grating. The diagram
shows the spectra of the first two orders, which may not be drawn to scale. The
first-order spectrum starts at an angle of 20° from the zeroth order. The respective
angular separations between the two ends (red and violet) of a spectrum are α
and β for the first and second order spectra. Which of the following statements
is/ are correct?
(1) In the first-order spectrum, P is the violet end.
(2) β is greater thanα.
(3) There is no third-order spectrum.
A. (3) only
B. (1) and (2) only
C. (2) and (3) only
D. (1), (2) and (3)
22. If two independent sources, each separately at a noise level of 70dB, are sounded
together, they will produce a noise level of
A. 70 dB
B. 73 dB
C. 90 dB
D. 140 dB
23. An aeroplane flies horizontally at a low altitude with a constant speed of 300ms-1.
It transmits a radio signal of frequency 30 MHz as it passes a receiving station.
What is the difference in the frequencies received a long time before and a long
time after the passage of the plane?
A. 10 Hz
B. 30 Hz
C. 60 Hz
D. 120 Hz
24. Two point objects each carrying charge 10 Q are separated by a distance d. The
force between is F. If half the charge on one object is transferred to other object
while at the same time the distance between them is doubled, what is the new
force between the two objects?
A. 0.19 F
B. 0.25 F
C. 0.75 F
D. 4.0 F
25. Two identical point charges are held a distance d apart by a non-conducting string
with tension T. If a third identical point charge is fixed at a distance of d/2 from
both of the first two point charges then what will be the new tension in the string.
A. 2T
B. 3T
C. 4T
D. 5T
26. An inexpansible vessel contains air at 50℃. What percentage of air remains in the
vessel if it is heated to 100℃ under constant pressure? (You may take the ice
point to be 273K)
A. 87%
B. 73%
C. 63%
D. 50%
27. The straight lines in the diagram represent electric field lines. Which of the
following statements about this electric field is/are correct?
(1) A stationary negative charge placed at Q tends to move to P.
(2) The electric flied strength at P is stronger than at Q.
(3) Work has to be done in moving a negative charge from R to P.
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
28. Which of the following quantities can be increased by increasing the voltage
across a metal wire?
(1) the average drift velocity of the conduction electrons
(2) the number of conduction electrons per unit volume
(3) the speed of the electric signal
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
29. A parallel plate capacitor is charged to a voltage, V. To double the energy stored
on the capacitor, the voltage between the plates would have to become:
A. 0.25V
B. 0.5V
C. 1.4V
D. 2.0V
30. A negative electrical charge is made to move clockwise in a circular path due to an
external magnetic field. What would be the direction of the magnetic field?
A. towards the top of the page
B. out of the page
C. into the page
D. towards the left
31. A parallel-plate capacitor with a slab of dielectric between the plates is charged by
being momentarily connected to a battery. The slab of dielectric is then removed.
Which of the following statements is/are true?
(1) The potential difference between the plates decreases.
(2) The electrical energy stored in the capacitor increases.
(3) Work is required to remove the dielectric.
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
32. Two 1000Ω resistors are connected in series to a 120 V electrical source. A
voltmeter with a resistance of 1000Ω is connected across the last resistor as
shown. What would be the reading on the voltmeter?
A. 80 V
B. 60 V
C. 40 V
D. 30 V
33. What is the current through the 3Ω resistor?
A. V / 2Ω
B. V / 3Ω
C. V / 4Ω
D. V / 5Ω
34. The picture below shows two perpendicular wires carrying conventional currents
I1 and I2 as shown.
How many points on the plane containing both wires with magnetic flux density
B=0?
A. A single point
B. Two points
C. A diagonal line through the origin
D. Two diagonal line through the origin
35. The graphs above show the variations of the collector current Ic with p.d. VCE
across the collector and the emitter for different values of base current Ib. What is
the current amplification factor β of the transistor?
A. 2
B. 100
C. 150
D. 200
36. When the transistor in the above circuit conducts the p.d. VBE between the base
and the emitter is 0.7V. The current amplification factor of the transistor is 200.
The transistor is said to be suitably biased for linear amplification if △ Vin = 0V,
Vout =3.0V. Calculate the value of R in proper biasing condition.
A. 15kΩ
B. 27kΩ
C. 53kΩ
D. 87kΩ
37. An additional mechanical load is applied to a rotating motor. Which of the
following is/are true?
(1) The motor will decrease in speed.
(2) The e.m.f induced in the rotating coil will decrease.
(3) More power will be drawn from the power supply.
A. (1) only
B. (1) and (2) only
C. (2) and (3) only
D. (1), (2) and (3)
38. An electron moves in a circular path in a uniform magnetic field of flux density
1.0 mT. If an α particle of the same speed is to follow an identical path, what
must be the magnetic field? Given that the mass of anα particle is 7200 times
that of an electron
A. 1800mT in opposition direction
B. 3600mT in opposition direction
C. 1800mT in same direction
D. 3600mT in same direction
39. A rectangle loop of wire in the plane of the paper starts outside a perpendicular
uniform magnetic field directed into the paper as shown. The loop is pulled with a
constant velocity through the magnetic field and out the other side. Assume the
resistance in the wire is large enough so that the back-emf is negligible. Which of
the following graphs would best represent the electric current n the wire as it
varies with time?
40. According to the uranium Disintegration Series, how many beta particles are
emitted when an atom of
218
84
Po decays to
206
82
Pb ?
A. 7
B. 6
C. 4
D. 3
41. Which statement best describes what occurs when the control rods are inserted
into nuclear reactor?
A. The number of fission reactions decreases because the control rods absorb
neutrons.
B. The number of fission reactions decreases because the control rods absorb
electrons.
C. The number of fission reactions increases because the control rods absorb
neutrons.
D. The number of fission reactions increases because the control rods absorb
electrons.
42. An X-ray tube emits X-rays with a minimum wavelength of 3.55 x 10-11m.
Estimate the potential difference between the cathode and the anode (target) in the
X-ray tube.
Planck constant = 6.63x10-34Js
Electronic charge = 1.6 x10-19C
Velocity of light in air = 3 x 108 ms-1
A. 20 000V
B. 25 000V
C. 30 000V
D. 35 000V
Given:
43. The energy levels of an atom of an element X are shown in the following diagram,
with values given in eV. Which electron transition will produce photons of
wavelength = 620nm?
(Planck’s constant = 6.6x10-34Js, 1eV= 1.6 x10-19J)
44. A radioactive source contains two materials. One decays by the emission of an α
particle with a half-life of 4 days while the other emits β particles with a
half-life of 3 days. The initial corrected count rate is 176s-1 but this becomes 80s-1
when apiece of tissue paper is placed between the source and the detector. What
will be the corrected count rate after 12 days without the tissue paper present?
A. 12s-1
B. 17s-1
C. 22s-1
D. 34s-1
45. A parallel-plate capacitor is formed by two square metal plates. To determine the
capacitance C, a student measures the length of side 1 and separation d of the
plates.
If the maximum percentage error of 1 = 5%
The maximum percentage error of d = 3%
Then the maximum percentage error for C will be
A. 8%
B. 13%
C. 22%
D. 28%
End of Section A
Section B
Answer any THREE questions from this Section. Write your answers in the
ANSWER BOOK provided.
1. (a) Explain the meaning of Newton’s second and third Laws of Motion.
(3
marks)
(b) Apply these laws to the rapid impact between two bodies, which were initially
moving with unequal velocities along the same direction, and show that linear
momentum is conserved. Explain whether the total kinetic energy is necessarily
conserved, or not.
(7 marks)
(c) Briefly discuss the conservation of energy in regard to
(i) the result of the Frank-Hertz experiment and
(ii) the energy spectrum of the β –particles emitted naturally by some
nuclei.
(No experimental circuit details or theoretical details are expected.)
(6 marks)
2. (a) Describe and explain briefly the methods adopted in the measurement of
(i) a steady magnetic field using a Hall probe, and
(ii) an alternating magnetic field using a search coil.
Compare the different physical mechanisms in these two methods and
derive any necessary mathematical expressions.
(11 marks)
(b) Describe an experiment to measure the charge/mass (e/m) ratio for electrons
using an electric field and magnetic field perpendicular to each other. (no
theory of the production of the magnetic field is expected.)
(5 marks)
3. (a) Unpolarized sunlight is incident horizontally on air molecules around O in the
earth’s atmosphere. Part of the light is transmitted horizontally and part is
scattered vertically downward.
Briefly explain which ray, the transmitted one or the scattered one, is plane
polarized and give the direction of the electric fields vector for this ray. Describe a
method to identify this polarized light ray.
(5 marks)
(b) Give an account of an everyday example involving polarized light. (3 marks)
(c) (i) State two differences between laser light and light emitted by a light bulb.
(ii) What is meat by ‘population inversion’? how do gas lasers rely on this to
operate?
(iii) State and explain two advantages of using laser for cutting over
mechanical devices.
(8 marks)
4. The figure below shows a typical stress-strain graph.
(a) What is the implication of the shape of the portion OA?
(2 marks)
(b) Explain the significance of the two points B and C.
(3 marks)
(c) What is the meanings of the following properties of solids and how do they
manifest themselves in the graph?
(i) Strength
(ii) Stiffness
(iii) Ductility
(6 marks)
(d) (i) Define the Young modulus and show how it can be determines from the
stress-strain graph.
(ii) the atoms in a solid can be imagined as being linked together by elastic
springs. Show that the Young modulus E is related to the microscopic quantities in
a solid by E = k/d, where k is the force constant of each elastic spring and d is the
atomic spacing.
(iii) State a typical order of magnitude of the Young modulus of steel.
(5 marks)
5. (a) With the aid of a circuit diagram, briefly describe how a reed switch works in
investigating the dependence of the charge stored in a parallel-plate capacitor on
(i) the area of overlap of the plates, and
(ii) the separation between the plates.
Show graphically the expected results.
(8 marks)
(b) What is the physical meaning of the reactance of a capacitor? On what factors
does the reactance of a capacitor depend?
(2 marks)
(c) (i) Sketch a graph of a typical X-rays spectrum and explain how the
characteristic and continuous parts of the spectrum are formed.
(ii) Why is there a definite minimum wavelength of the X-rays produced?
(6 marks)
End of Section B