00 AL Physics/M.C./P.1
2000 Hong Kong Advanced Level Examination
AL Physics
Multiple Choice Questions
1.
F
A
B
3.
R
Two books A and B are placed on a
horizontal table surface as shown. A
horizontal force F is applied to A but the
system remains stationary. Which of the
following statements is/are correct?
Q
W
A light rigid rod PQ is hinged smoothly to
the wall at one end while the other end is
connected by an inextensible string to a
point R directly above P. A weight W is
suspended from a point on the rod. If the
rod remains horizontal, which of the
following change(s) would increase the
tension in the string?
(1) The frictional force acting on B by the
table surface is greater than F.
(2) The frictional force acting on A by B
is towards the left.
(3) The system would remain stationary if
F is applied to B instead.
A.
B.
C.
D.
E.
2.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(1) Shifting the weight towards Q
(2) Replacing the string with a shorter
one and connecting it to the midpoints of PQ and PR
(3) Replacing the string with a longer one
and connecting it to a point higher
than R
In which of the following situations is the
magnitude of the normal reaction of the
supporting surface always equal to the
weight of the body?
(1) A ball bouncing vertically on a
horizontal ground is in contact with
the ground.
(2) An astronaut in a spacecraft which
performs circular motion around the
earth.
(3) A boy standing in a lift which is
moving vertically upward with a
uniform velocity.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
P
A.
B.
C.
D.
E.
4.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
A student holds one end of a string to
which a block of mass 8 kg is tied at the
other end. He raises the block with an
acceleration by pulling the string in an
upward direction. If the maximum tension
that the string can withstand is 120 N, find
the maximum acceleration of the block
before the string breaks.
A.
B.
C.
D.
E.
5.0 ms-2
7.5 ms-2
10.0 ms-2
12.5 ms-2
15.0 ms-2
00 AL Physics/M.C./P.2
5.
A trolley of mass 0.5 kg moves with a
certain acceleration down a runway which
is inclined to the horizontal at 15. If the
angle of inclination is increased to 20, the
acceleration of the trolley would be
doubled. Find the average frictional force,
assuming the same in both cases, acting on
the trolley.
A.
B.
C.
D.
E.
0.72 N
0.80 N
0.88 N
0.96 N
1.04 N
(3) The gravitational potential energy lost
by the ball is equal to the strain
energy stored in the spring.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
8.
N
r
6.
Two objects A and B of masses m and 2m
respectively are initially at rest on a
smooth, horizontal surface. If each of
them is acted upon by the same force for
the same period of time, the ratio of the
gain in kinetic energy of A to that of B is
A.
B.
C.
D.
E.

mg
A car of mass m is moving with speed v on
a banked road along a circular path of
horizontal radius r.
The angle of
inclination of the road is . If the
centripetal force arises entirely form a
component of the normal reaction N from
the road, which of the following relations
is correct?
2:1
1:2
1:1
1:4
4:1
A. N cos  = mg
B. N = mg cos 
gr
C. v2 =
sin 
gr
D. v2 =
tan 
7.
h
E.
9.
A light spring is fixed to the bottom of a
vertical tube. A ball is released from rest
at a height h above the upper end of the
spring as shown. After rebounding several
times the ball eventually comes to rest and
stays on top of the spring. Assume all
contact surfaces are smooth and the spring
obeys Hooke’s law throughout. Which of
the following statements is/are correct?
(1) The compression of the spring is
proportional to the mass of the ball.
(2) The compression of the spring is
independent of the height h.
N
mv 2
=
tan 
r
X and Y are two planets. Each of them has
a low-altitude satellite revolving in a
circular orbit close to the planet. If the
two satellites are observed to have the
same period, then X and Y must have
nearly the same
A.
B.
C.
D.
mass.
average density.
radius.
acceleration due to gravity at the
planet’s surface.
E. gravitational potential at the planet’s
surface.
00 AL Physics/M.C./P.3
10. A small block of mass 0.1 kg is suspended
from the ceiling by a light spring of force
constant 12 Nm-1. If the block is projected
vertically downwards with a speed of 0.5
ms-1 from its equilibrium position, what is
the maximum acceleration of the block in
its subsequent motion?
A.
B.
C.
D.
E.
Which of the following is a possible
reason for this?
A. The effect due to air resistance is not
negligible.
B. The stop watch used for the
experiment runs too slowly.
C. The length of the string has been
taken as the effective length of the
pendulum.
D. The experiment has been performed at
a place above sea-level.
E. The experiment has been performed at
a place below sea-level.
5.0 ms-2
5.5 ms-2
6.0 ms-2
6.5 ms-2
7.0 ms-2
11.
13.
glass
tube
L

A

rubber
bung
W
A student performing a centripetal force
experiment whirls a rubber bung attached
to one end of a string which passes
through a glass tube with smooth
openings, and has weight W hanging at its
other end. The weight of the rubber bung
is much smaller that W. The rubber bung
is set into a horizontal uniform circular
motion with angular speed  while the
length off the string beyond the upper
opening of the glass tube is L and this
portion of the string makes an angle  with
the vertical as shown. Which of the
following statements is/are correct?
(1) If L is kept constant,  will decrease
with .
(2) If  is kept constant, L will increase
with .
(3) When W increases,  will increase.
A.
B.
C.
D.
E.
(1) only
(2) only
(3) only
(1) and (2) only
(2) and (3) only
12. A student used a simple pendulum to
measure acceleration due to gravity at the
earth’s surface. The experimental value
was found higher than the standard value.
On a smooth horizontal surface, a block
connected to the wall with a light spring
performs simple harmonic motion of
amplitude A as shown. If the amplitude is
reduced to A/2, which of the following
quantities would be halved?
(1) the maximum velocity of the block
(2) the maximum elastic potential energy
stored in the spring
(3) the period of oscillation of the block
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
14. With his arms and legs outstretched, a
diver leaves a high-diving board with
some initial angular velocity. Before he
enters the water, which of the following
statements is INCORRECT? (Neglect air
resistance.)
A. His angular momentum about the
centre of gravity remains constant.
B. No external force acts on him.
C. His loss in potential energy becomes
his kinetic energy.
D. He can decrease his moment of inertia
by pulling his arms and legs to his
chest.
00 AL Physics/M.C./P.4
E. He can make more turns before
reaching the water surface by coiling
up his body.
C. becomes partly elastic potential and
partly kinetic in the string.
D. converts into internal energy and is
dissipated as heat energy in the string.
E. becomes momentarily zero.
15.
17.
paper cone
pendulums
(loaded with
metal rings)
string
A
Displacement
of air particles
+
_
heavy bob
B
C
(1) P is a centre of compression.
(2) The air particle at P has the greatest
kinetic energy.
(3) The air particle at P is moving
towards right.
(1) B has the largest amplitude among the
three paper cone pendulums.
(2) All the paper cone pendulums are
oscillating with the same frequency.
(3) A and C are approximately in
antiphase.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
position
The above figure shows an instantaneous
wave profile representing a sound wave
travelling to the right in air. Which of the
following about the part of the wave at P
at this instant is/are correct? (Take the
displacement towards right as positive.)
The figure shows a variation of Barton’s
pendulum. A, B and C are three paper
cone pendulums of different lengths
suspended from the string. The heavy bob
is pulled well aside and released so that it
oscillates on a plane perpendicular to the
paper. The paper cone pendulums are
forced into oscillations. When the motion
settles down after a short time, which of
the following statements is/are correct?
A.
B.
C.
D.
E.
P
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
18.
16.
Two transverse pulses travel towards each
other along a stretched string as shown.
They are identical and symmetric in shape
but one is inverted. At the moment the
pulses pass each other the string becomes
straight. At this moment the wave energy
A. becomes wholly elastic potential in
the string.
B. becomes wholly kinetic due to
transverse motion of the string.
1 cm
A dot vibrator is moving across the surface
of water in a ripple tank with a steady
speed as shown. The figure represents the
water surface showing the pattern of the
water waves against a background of
centimetre squares. The speed of the
water waves is 20 cms-1. What is the
speed of the dot vibrator?
00 AL Physics/M.C./P.5
A.
B.
C.
D.
E.
10 cms-1
8 cms-1
5 cms-1
4 cms-1
2 cms-1
(1) The lens L must be a concave lens.
(2) The point object must lie along the
line OS.
(3) The image of the point object must be
virtual.
A.
B.
C.
D.
E.
19.
air
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
glass
21.
thin film
+Q
A glass lens is made non-reflecting for
yellow light by coating it with a thin film
of transparent material of a refractive
index less than that of glass. Which of the
following statements is/are correct?
d
+2q
d
In the above arrangement, two small test
charges +q and +2q are brought from
infinity to the positions shown. The two
charges are collinear with another charge
+Q and their mutual separation is d.
Which of the following statements is/are
correct?
(1) The surface of the glass lens appears
yellow in white light.
(2) The minimum thickness of the film is
¼ of the wavelength of yellow light in
the film.
(3) As a result of the destructive
interference between the light rays
reflected from the two interfaces,
energy which would have been wasted
as reflected light increases the amount
of transmitted light.
A.
B.
C.
D.
E.
+q
(1) Charge +q is at a higher potential than
charge +2q.
(2) The work done in bringing the
charges +q and +2q from infinity to
their respective positions is the same.
(3) The potential energy of the system
would increase if d decreases.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
20.
22.
L
P
X
Q
O
Y
S
In the above figure, XY is the principal
axis of a lens L. PQ and OS are two
refracted rays from L which originate from
a point object placed on the left side of L.
Which of the following deductions is/are
correct?
P
Q
R
The figure shows a pattern of electric field
lines in which P, Q and R are points
marked on one of the field lines with PQ =
QR. If the potential at P is 0 V, which of
the following can give the possible
potentials at Q and at R?
00 AL Physics/M.C./P.6
A.
B.
C.
D.
E.
Potential at Q
-200 V
-200 V
-200 V
+200 V
+200 V
A.
B.
C.
D.
E.
Potential at R
-450 V
-400 V
-350 V
+350 V
+450 V
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
25.
S
23.
R
0.2 A 5 
O
3
0.3 A
1
R
The figure shows some of the resistors in a
network of resistors. The magnitudes and
directions of some of the currents are
marked as shown. Find the magnitude and
direction of the current passing through
the resistor R.
A.
B.
C.
D.
E.
0.2 A from right to left
0.2 A from left to right
0.4 A from right to left
0.4 A from left to right
It cannot be determined as the value
of R is not given.
24.
internal resistance 4 
P
Q
Four parallel long straight conductors
carrying currents of equal magnitude pass
vertically through the four corners of a
square PQRS. The current is directed into
paper in one conductor and is directed out
of paper in the other three conductors.
Which of the following arrangement can
produce a resultant magnetic induction at
the centre O of the square in the direction
shown?
Current into paper Current out of paper
A.
P
Q, R, S
B.
Q
P, R, S
C.
R
P, Q, S
D.
S
P, Q, R
E. It is impossible to produce a resultant
magnetic induction at O in the
direction shown.
R
In the above circuit, the internal resistance
of the battery is 4 . R is a variable
resistor.
Which of the following
statements about the circuit is/are correct?
(1) If the resistance of R is very small, the
terminal potential difference of the
battery is very small but the power
dissipated in the battery is large.
(2) If the resistance of R is very large, the
current in the circuit is very small but
most of the power supplied by the
battery is dissipated by R.
(3) If the resistance of R is 4 , the power
supplied to R by the battery is at a
maximum.
26. Two parallel plates are connected to an
E.H.T. of 4.5 kV. Electric breakdown
occurs when the separation of the plates is
reduced to 1.5 mm.
Estimate the
maximum acceleration of an electron
between the plates.
(Given:
charge of an electron = 1.6  10-19 C;
mass of an electron = 9.1  10-31 kg)
A.
B.
C.
D.
E.
4.0  107 ms-2
1.0  109 ms-2
1.2  1012 ms-2
1.6  1015 ms-2
5.3  1017 ms-2
00 AL Physics/M.C./P.7
27. A beam of charged particles passes
undeflected through a region of crossed
uniform electric and magnetic fields.
Which of the following must be common
to the particles making up this beam?
A.
B.
C.
D.
E.
I
II
III
charge to mass ratio
velocity
mass
sign of charge
magnitude of charge
(1)
I
II
II
III
III
A.
B.
C.
D.
E.
28. When a simple motor rotating at a steady
speed is suddenly jammed and comes to a
stop, which of the following statements
is/are correct?
(2)
II
II
III
II
III
30.
X
(1) The rate of change of magnetic flux
through the coil of the motor will be
very large.
(2) A large e.m.f. will be induced in the
coil of the motor.
(3) A large current will flow through the
coil of the motor.
A.
B.
C.
D.
E.
Y
6.0 V
Z
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
In the above circuit, the battery has an
e.m.f. of 6.0 V and all the capacitors are
identical. Initially none of the capacitors
are charged. The switch is first connected
to X and then to Y. What is the final
potential difference between Z and Y?
29.
A.
B.
C.
D.
E.
D
R
1.0 V
1.5 V
2.0 V
2.4 V
3.6 V
31.
The figure shows a bridge rectifier circuit
in which all the diodes are assumed ideal.
The source is a sinusoidal a.c. supply.
Which of the following traces (I, II or III)
would be displayed on a CRO connected
across the load resistor R if
(1) the diode D were reversed in the
circuit,
(2) the diode D were removed leaving a
break in the circuit?
I
0
t
A constant p.d. is applied to a solenoid.
The variation of current I with time t is as
shown. Which of the following can be
deduced from the shape of the graph?
A. The solenoid has resistance as well as
inductance.
B. The inductance of the solenoid
decreases as time increases.
00 AL Physics/M.C./P.8
C. The inductance of the solenoid
increases as time increases.
D. The e.m.f. induced in the solenoid is
proportional to the current.
E. The e.m.f. induced in the solenoid is
proportional to the rate of change of
current.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
34.
32.
L
B
C
A
L
S
In the above circuit, A and B are identical
light bulbs and L is a pure iron-cored
inductor.
Which of the following
statements is/are correct?
(1) When switch S is closed, bulb A will
light up first.
(2) After switch S is closed for some
time, A and B are equally bright.
(3) When switch S is open, bulb A will go
out first.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
The figure shows an LC oscillatory circuit
in which C is a capacitor and L is an aircored inductor. At a certain instant the
magnetic flux inside L is pointing upward
as shown.
Which of the following
descriptions of the capacitor is/are
possible at this instant?
(1) The capacitor is charging with
upper plate positively charged.
(2) The capacitor is charging with
lower plate positively charged.
(3) The capacitor is discharging with
upper plate positively charged.
(4) The capacitor is discharging with
lower plate positively charged.
A.
B.
C.
D.
E.
33.
C
R
A capacitor C and a resistor R are
connected in series to an a.c. source of
constant output voltage. Which of the
following statements is/are correct?
(1) The current leads the applied voltage.
(2) The impedance of the circuit
decreases when the frequency
increases.
(3) The power factor of the circuit
decreases when the frequency
increases.
(1) only
(1) or (3) only
(1) or (4) only
(2) or (3) only
(2) or (4) only
the
the
the
the
00 AL Physics/M.C./P.9
35. The following diagrams show the currents
of sinusoidal waveform and square
waveform passing in turn through a
resistor. The average power dissipated is
the same in both cases.
B. When r < r0, U increases as r
decreases.
C. When r > r0, U increases as r
increases.
D. When r is very large, U is close to
zero.
E. When U is very large, the force
between the two molecules is
repulsive.
I/A
1
0
T
2T
time
38.
Q
p/kPa
I/A
I0
0
T
2T
R
time
P
0
Given that the peak value of the sinusoidal
current is 1 A. What is the value of I0 of
the square waveform current?
A.
1
A
2
1
A
2
C. 1 A
S
T/K
A fixed mass of an ideal gas goes through
the three processes from P to S indicated
in the above p-T diagram: (1): P  Q, (2):
Q  R, (3): R  S. During which of the
above processes is work done by the gas
on the surroundings?
B.
D.
2A
E.
2 2A
36. The average stress in the legs of a man
standing upright is S. If the dimensions of
the man are doubled while the average
density of the body remains the same, the
average stress in the legs would be
A.
B.
C.
D.
E.
S/2.
S.
2S.
4S.
8S.
37. Let r be the separation of two molecules in
a solid and U be the intermolecular
potential energy of these two molecules.
When r = r0, the attractive force between
the two molecules is equal to their
repulsive force. Let U = 0 when r = r0.
Which of the following statements is
INCORRECT?
A. U is non-negative for all values of r.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(1) and (3) only
(2) and (3) only
39. Which of the following statements
concerning a real gas is/are correct?
(1) Collisions between molecules and the
wall of a container are not perfectly
elastic.
(2) The volume of the molecules cannot
be neglected.
(3) Intermolecular forces cannot be
neglected.
A.
B.
C.
D.
E.
(1) only
(2) only
(3) only
(1) and (2) only
(2) and (3) only
00 AL Physics/M.C./P.10
40.
42.
Energy
+15 V
Vin
0
Vout
Q
-15 V
-4E
P
-6E
The energy levels of a certain atom are as
shown. Which of the following may
undergo an inelastic collision with the
atom?
In the operational amplifier circuit shown
the feedback is provided by a
potentiometer PQ.
The gain of the
amplifier circuit is
(1) an electron with kinetic energy 3E
(2) a photon with energy 2E
(3) a photon with energy 3E
A.
B.
C.
D.
E.
(1) zero when the sliding contact is at P.
(2) one when the sliding contact is at Q.
(3) independent of the resistance value of
the potentiometer PQ.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
A.
B.
C.
D.
E.
41. In a series of photoelectric emission
experiments on a certain metal surface,
relationships between the following
physical quantities were investigated.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
43.
N
f
I
i
K
=
=
=
=
frequency of incident light
intensity of incident light
photoelectric current
maximum kinetic energy
photoelectrons
P
of
y
x
0
Two of these quantities, when plotted on a
graph of y against x, would give a straight
line through the origin. Which of the
following correctly identifies x and y?
(Assume the frequencies used are greater
than the threshold frequency.)
A.
B.
C.
D.
E.
x
K
f
f
I
I
y
i
K
i
K
i
The diagram shows the path of an particle as it approaches a massive nucleus
at N. At point P the -particle is nearest
to the nucleus. Which of the following
statements is correct?
A. At P the electric potential energy of
the -particle is at a minimum.
B. At P the total energy of the -particle
is the minimum.
C. At P the angular momentum of the particle about N is at a minimum.
D. If the initial kinetic energy of the particle was greater, the distance
between P and N would be larger.
E. If the atomic number of the nucleus
was greater, the distance between P
and N would be larger.
00 AL Physics/M.C./P.11
44. A GM counter is placed close to and in
front of a radioactive source which emits
both  and  radiation. The count rate
recorded is 500 counts per minute while
the background count rate is 50 counts per
minute. Three different materials are
placed in turn between the source and the
counter.
The following results are
obtained.
Material
Recorded count rate /
counts per minute
500
x
y
(Nil)
Cardboard
1 mm of
aluminium
5 mm of lead
z
Which of the following is a suitable set of
values for x, y and z?
A.
B.
C.
D.
E.
x
y
z
350
350
350
150
150
350
150
150
150
50
150
50
0
50
50
45. The following equations represent some
typical nuclear reactions:(I)
9
4
Be  11H  63 Li  42 He
(II)
2
1
H  31H  42 He  01n
(III)
235
92
U  01n  148
57 La 
85
35
Br  3 01n
Which of the following descriptions of
these reactions is/are correct?
(1) Reaction (I) represents a spontaneous
-decay.
(2) Reaction (II) represents a nuclear
fusion.
(3) Reaction (III) represents a chain
reaction.
A.
B.
C.
D.
E.
- End of Paper -
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
00 AL Physics/M.C./P.12
Question No.
Key
Question No.
Key
1.
2.
3.
4.
5.
D
B
C
A
C
26.
27.
28.
29.
30.
E
B
B
D
C
6.
7.
8.
9.
10.
A
C
A
B
B
31.
32.
33.
34.
35.
A
C
C
D
C
11.
12.
13.
14.
15.
C
B
A
B
E
36.
37.
38.
39.
40.
C
D
E
E
C
16.
17.
18.
19.
20.
B
E
A
D
D
41.
42.
43.
44.
45.
E
D
E
A
D
21.
22.
23.
24.
25.
E
A
A
E
D