Download 1. Which of the following pairs of quantities of a moving object must

96 AL Physics/M.C./P.1
1996 Hong Kong Advanced Level Examination
AL Physics
Multiple Choice Question
1.
Which of the following pairs of quantities
of a moving object must be in the same
direction?
starting from the moment when the object
leaves one’s hand up to the time when it
returns to the ground? (Take downward
as positive.)
(1) acceleration and change in momentum
(2) displacement and velocity
(3) velocity and acceleration
A.
a
g
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
0
t
-g
B.
2.
a
In which of the following cases is the
resultant force on the object zero?
g
0
(1) a satellite moving round the earth
(2) a feather falling freely in a vacuum
cylinder in a laboratory
(3) a gas bubble rising with terminal
velocity in water
t
-g
C.
a
A.
B.
C.
D.
E.
3.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
g
0
t
-g
Two satellites of the same mass travel
around the earth in circular orbits of
different radii. The satellite in the orbit
with smaller radius has
D.
a
g
0
A. a greater speed.
B. a longer period.
C. a smaller acceleration towards the
earth’s centre.
D. a greater angular momentum about the
earth’s centre.
E. a greater sum of gravitational
potential energy and kinetic energy.
t
-g
E.
a
g
0
t
4.
An object is thrown vertically upward and
experiences an air resistance opposing its
motion with magnitude proportional to its
speed. Which of the following graphs
best represents the variation of the
acceleration, a, of the object with time, t,
-g
5.
96 AL Physics/M.C./P.2
A small object P of mass 0.3 kg is
attached to one end of a light, rigid rod of
length 0.5 m, which is free to rotate about
the other end O as shown. The object is
swung to rotate in a vertical circle so that
it attains a speed of 2 ms-1 at its topmost
position. What is the force exerted on
one end of the rod at this instant?
A
B
A.
B.
C.
D.
E.
The figure shows two blocks A and B,
each of mass m, connected by two light
springs to a fixed support. Each spring
has a force constant k. What is the total
extension of the system when it is at static
equilibrium?
8.
A.
B.
C.
D.
E.
mg/(2k)
mg/k
3mg/(2k)
2mg/k
3mg/k
a compressive force of 0.6 N
a tensional force of 0.6 N
a tensional force of 2.4 N
a tensional force of 5.4 N
a compressive force of 5.4 N
Three uniform wires, of same length and
mass but with different shapes, are hinged
to an axis passing through O and
perpendicular to the plane of the paper as
shown. Arrange their moments of inertia
about O in ascending order of magnitude.
(1)
6.
X
m
u
Y
Z
m
2m
X, Y and Z are three spheres of the same
size but with masses m, m and 2m
respectively, lying on a smooth horizontal
track with Y and Z in contact as shown.
X is moving to the right with velocity u
and makes a head-on collision with Y. If
all collisions are perfectly elastic, which of
the following gives the possible velocities
of the three spheres after all collision?
(Take to the right as positive.)
A.
B.
C.
D.
E.
X
0
0
-u/3
0
u/4
Y
0
u/3
0
-u/3
u/4
Z
u/2
u/3
2u/3
2u/3
u/4
7.
P
0.5 m
O
(2)
O
A.
B.
C.
D.
E.
9.
(3)
O
O
(1), (2), (3)
(2), (1), (3)
(1), (3), (2)
(2), (3), (1)
(3), (2), (1)
A system A oscillating at its natural
frequency fA is coupled to a system B of
natural frequency fB, and causes system B
to oscillate. When the steady state is
reached, which of the following statements
is/are correct?
(1) System B oscillates at frequency fA.
(2) The amplitude of system B depends
on the difference of fA and fB.
(3) The rate of transfer of energy from
system A to B is high when fA is close
to fB.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
96 AL Physics/M.C./P.3
10. A metre rule is clamped horizontally to the
edge of a bench so that most of its length
overhangs and it is free to vibrate with
vertical simple harmonic motion. The tip
of the rule vibrates with an amplitude of
3.5 cm and a maximum speed of 1.0 ms-1.
What is the frequency of vibration of the
rule?
A.
B.
C.
D.
E.
E. (1), (2) and (3)
14.

3.0 Hz
3.5 Hz
4.0 Hz
4.5 Hz
5.0 Hz
Monochromatic light of wavelength 589
nm is shone normally on a wedge-shaped
thin air film to form interference fringes.
If the distance between the sixth and
ninety-sixth dark fringes is 15.8 mm,
calculate the angle of the wedge, .
11. The least separation between two points

with a phase difference of
on a
6
progressive wave is 0.05 m. If the
velocity of the wave is 150 ms-1, the
frequency of the wave is
A.
B.
C.
D.
E.
125 Hz.
250 Hz.
375 Hz.
500 Hz.
1 000 Hz.
A.
B.
C.
D.
E.
0.024°
0.048°
0.072°
0.096°
0.190°
15.
S second-order
R spectrum


grating
Q first-order
P spectrum
white
12. When monochromatic light travels from
glass to air, the emergent light, relative to
the incident light, shows an increase in
(1) frequency.
(2) wavelength.
(3) velocity.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
13. When a beam of unpolarized light
travelling in air falls on a water surface, it
is possible to find an angle of incidence
such that
(1) all the light is reflected.
(2) the light passing into water is plane
polarized.
(3) the reflected light is plane polarized.
A.
B.
C.
D.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
light
zeroth order
20°
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
 and  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)  is greater than .
(3) There is no third-order spectrum.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
16. The straight lines in the diagram represent
electric field lines.
Which of the
Q
P
96 AL Physics/M.C./P.4
following statements about this electric
field is/are correct?
E. 60 cm
19. The image of the moon is focused on a
screen by a converging lens of focal length
20 cm. If the moon subtends an angle of
9.5  10-3 radian at the centre of the lens,
calculate the diameter of the image.
(1) A stationary negative charge placed at
Q tends to move to P.
(2) The electric field strength at P is
stronger than that at Q.
(3) Work has to be done in moving a
negative charge from R to P.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
17. Which of the following statements is/are
correct?
(1) Radio waves can be polarized.
(2) Ultrasonic waves are electromagnetic
in nature.
(3) All standing waves are transverse
waves.
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
4.8  10-2 cm
9.5  10-2 cm
1.9  10-1 cm
3.8  10-1 cm
7.6  10-1 cm
20. 3-cm microwaves are used in a radar speed
trap. When the emitted and reflected
signals are superposed, beats are
produced.
Find the minimum beat
frequency above which a driver would be
prosecuted for exceeding a speed limit of
100 kmh-1.
A.
B.
C.
D.
E.
1 000 Hz
1 900 Hz
2 400 Hz
3 400 Hz
4 700 Hz
21. A parallel-plate capacitor is charged by a
constant voltage source. With the plates
remaining connected to the source, the
plate separation, d, is then gradually
increased from an initial value d0. Which
of the following graphs best shows the
relationship between the energy, U, stored
in the capacitor and plate separation, d?
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
18.
M
L
A.
U
O
80 cm
0
A small object O is placed at the focus of a
convex lens L as shown. A concave
mirror M is placed 80 cm behind the lens.
If the focal length of L is 50 cm and the
final image formed by this system is at
infinity, the focal length of M is
A.
B.
C.
D.
20 cm
30 cm
40 cm
50 cm
d
d0
B.
U
0
d
d0
C.
96 AL Physics/M.C./P.5
U
24.
G
0
1 k
E
d
3V
d0
500 
2 k
D.
U
0
In the above circuit, the galvanometer
reading is zero.
If both cells have
negligible internal resistance, the e.m.f. of
the cell E is
d
d0
A.
B.
C.
D.
E.
E.
U
0
d
d0
6 V.
7 V.
8 V.
9 V.
10 V.
25. Six wires, each of resistance 1 , are
joined to form a regular tetrahedron
ABCD. A current of 2 A flows across the
tetrahedron at A and B.
22. A charged capacitor is connected across a
resistor. Its voltage drops to one-third of
the original value in 10 s. Find the time
constant of the circuit.
A.
B.
C.
D.
E.
C
2A
A
(1) Points C and D are of the same
potential.
(2) The current in wire AC is 0.5 A.
(3) The potential drop across AB is 1 V.
A.
B.
C.
D.
E.
A. zero
5Q
B.
4  0r
D.
E.
5Q 2
4 0r
5Q 2
4  0r 2
5Q
4  0r 2
D
Which of the following statements is/are
correct?
23. Five identical point charges, each of
charge Q, are fixed evenly on a circle of
radius r. How much work has to be done
to bring another point charge Q from
infinity to the centre of the circle? (0 =
permittivity of free space)
C.
B
2A
4.1 s
9.1 s
11 s
25 s
30 s
26.
(1) only
(2) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
P
Q
II
III
I
V
S
IV
R
96 AL Physics/M.C./P.6
Four infinitely long straight parallel wires
P, Q, R, S carrying equal currents are
situated at the corners of a square as
shown. The currents in P, Q are into
paper and those in R, S are out of paper.
What is the direction of the resultant
magnetic induction at the centre of the
square?
A.
B.
C.
D.
E.
28.
S
E
L
R2
R1
I
II
III
IV
V
In the above circuit, both the cell E and
the inductor L have negligible resistance.
The e.m.f. of E is 10 V, and the resistors
R1 and R2 are of resistances 2  and 3 
respectively.
What will the current
drawn from the cell be
27.
magnetic
flux
(I) at the moment when switch S is
closed?
(II) when the steady state is reached after
closing switch S?
S
load
soft iron core
A.
B.
C.
D.
E.
The diagram shows the circuit of an ideal
transformer with a load connected to the
secondary. Which of the following is/are
correct at the moment when switch S is
closed?
(I)
2A
2A
2A
5A
0A
(II)
0A
2A
5A
0A
5A
29.
(1) The magnetic flux in the soft iron core
will be reduced.
(2) The back e.m.f. in the primary will
drop.
(3) The primary current will increase.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
V
V
0
t1 t2
time
C
A sinusoidal voltage V is applied across a
capacitor C. Which of the following
statements is/are correct?
(1) At time t1, the charge in the capacitor
is at a maximum.
(2) At time t2, the current in the circuit is
at a maximum.
(3) The current in the circuit leads the
voltage V.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
96 AL Physics/M.C./P.7
30.
An input voltage (Vin) of 2.0 V is applied
to an ideal operational amplifier connected
as shown. The current flowing through
the 8 k resistor is
A
B
output
A.
B.
C.
D.
E.
Which of the following pairs of inputs
would give a HIGH output from the above
combination of NAND gates?
Input A
(1) LOW
(2) LOW
(3) HIGH
A.
B.
C.
D.
E.
Input B
HIGH
LOW
HIGH
33.
y
A
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
O
B
31.
magnetic field
out of paper
+6 V
1 k
10 k
Vout
Vin
0V
In the above transistor circuit, the voltage
across the base and the emitter is 0.5 V
when the transistor works. The current
amplification factor of the transistor is 80.
What input voltage (Vin) would give an
output voltage (Vout) of 4 V?
A.
B.
C.
D.
E.
0.25 mA from X to Y.
0.80 mA from X to Y.
0.80 mA from Y to X.
1.0 mA from X to Y.
1.0 mA from Y to X.
0.25 V
0.50 V
0.75 V
1.00 V
1.25 V
magnetic field
into paper
Two uniform magnetic fields of equal
magnitude but with one into paper and the
other out of paper, are separated on the
two sides of the y-axis as shown. A wire
is bent into a closed loop OABO, which is
shaped as a quarter of a circle. It is
rotated uniformly in a clockwise direction
about O on the plane of the paper.
Which of the following graphs best shows
the variation of current, I, in the loop with
time, t, in one revolution?
A.
I
0
t
B.
I
32.
0
8 k
t
+15 V
Y
X
-15 V
Vin
2 k
C.
96 AL Physics/M.C./P.8
I
0
to CRO
t
D.
I
C.
0
t
to CRO
E.
I
D.
0
t
to CRO
34. The reactance of a solenoid depends on
E.
(1) the frequency of the applied a.c.
voltage.
(2) the inductance of the solenoid.
(3) the resistance of the solenoid.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
to CRO
36.
U
O
35.
r
Q
P
When a CRO is connected to a circuit, the
trace obtained is as shown above. To
which of the following circuits has the
CRO been connected?
A.
to CRO
B.
The potential energy, U, of a pair of atoms
as a function of their separation, r, is
shown for two crystalline solids P and Q.
From these curves alone, one may
conclude that
(1) the equilibrium separation of the
atoms in P is greater than that in Q.
(2) P is stiffer than Q.
(3) the energy required to separate two
atoms of P in equilibrium is more than
that for Q.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
96 AL Physics/M.C./P.9
A. The most stable state of the atom
corresponds to the level -12 eV.
B. If the atom is at the level -4 eV, it can
absorb a photon of energy 4 eV.
C. If the atom is at the level -4 eV, it can
emit a photon of energy 8 eV.
D. If the atom is at the level -12 eV and
collides with an electron of kinetic
energy 10 eV, it can change to the
level -4 eV.
E. If the atom is at the level -12 eV and
collides with two photons, each of
energy 4 eV, it can change to the level
-4 eV.
37. Which of the following statements is/are
correct?
(1) The boiling point of pure water
increases with atmospheric pressure.
(2) The water molecules in 100 °C steam
have a higher r.m.s. speed than those
in pure water boiling at 100 °C.
(3) When pure water is boiling, the
supplied
energy
becomes
the
intermolecular potential energy and
the kinetic energy of the water
molecules.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
40.
A
ball
B
N
air stream
38. Of the three common materials, copper,
glass and rubber, which two best illustrate
the properties described in the following
statements when each is stretched under
room temperature?
(1) It obeys Hooke’s law almost up to its
breaking point.
(2) It tolerates a large strain when
exhibiting elastic behaviour.
A.
B.
C.
D.
E.
(1)
copper
copper
glass
glass
rubber
(2)
glass
rubber
copper
rubber
glass
39.
energy
0 eV
-1 eV

A steady stream of air is ejected from a
nozzle N and keeps a small polythene ball
staying in mid air as shown. The nozzle
and the direction of air stream make an
angle  with the horizontal. Which of the
following statements is/are correct?
(1) The ball spins in an anti-clockwise
direction.
(2) Air flows faster on side A than side B
of the ball.
(3) When angle  increases, the ball spins
more slowly.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
41. A radioactive source is tested as follows:
-4 eV
-12 eV
A hypothetical atom has only four energy
levels as represented above.
It can
change from any one level to any other.
Which of the following statements about
this hypothetical atom is INCORRECT?
Absorber placed
between source and GM
counter
(1) Thin aluminium foil
(0.2 mm)
(2) Thin lead sheet
(2 mm)
(3) Thick lead sheet
(20 mm)
Effect on count
rate
Falls appreciably.
No significant
difference with
(1).
Falls below that in
(1).
96 AL Physics/M.C./P.10
What type(s) of radiation does the source
emit?
A.
B.
C.
D.
E.
 only
 only
 only
 and  only
 and  only
44. A counter is placed near a very weak
radioactive source which has a half-life of
1 hour.
The counter registers 100
counts/min at noon and 80 counts/min at 1
p.m.
The expected count rate, in
counts/min, at 3 p.m. on the same day is
42. A metal surface is illuminated with
monochromatic light so that it emits
photoelectrons. The maximum kinetic
energy of the emitted photoelectrons
depends on
(1) the distance of the metal surface from
the light source.
(2) the work function of the metal
surface.
(3) the wavelength of the incident
monochromatic light.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
A.
B.
C.
D.
E.
40
50
55
60
65
45. The period of oscillation, T, of a simple
pendulum is related to its length, l, by the
l
.
To find
g
experimentally the acceleration of free fall
by using a simple pendulum, a student
takes the following measurements:
formula
T  2
time for 15 oscillations: 14.4  0.2 s
length of the pendulum: 0.229  0.001 m
43. Given: mass of proton = 1.0073 u
mass of neutron = 1.0087 u
binding energy of an alpha particle
= 28.396 MeV
1 u is equivalent to 931 MeV
The mass of an alpha particle is
C. 4.0320 u.
D. 4.0625 u.
E. 4.1540 u.
Which of the following is the most
appropriate way of expressing the result?
A.
B.
C.
D.
E.
A. 3.9100 u.
B. 4.0015 u.
- End of Paper -
9.8  0.2 ms-2
9.8  0.3 ms-2
9.81  0.32 ms-2
9.810  0.179 ms-2
9.810  0.315 ms-2
96 AL Physics/M.C./P.11
Question No.
Key
Question No.
Key
1.
2.
3.
4.
5.
A
B
A
C
E
26.
27.
28.
29.
30.
A
E
C
E
A
6.
7.
8.
9.
10.
C
A
B
E
D
31.
32.
33.
34.
35.
C
E
D
C
E
11.
12.
13.
14.
15.
B
D
B
D
E
36.
37.
38.
39.
40.
E
A
D
E
D
16.
17.
18.
19.
20.
C
A
B
C
B
41.
42.
43.
44.
45.
D
D
B
E
B
21.
22.
23.
24.
25.
A
B
C
D
E