Download 2001-CE-PHY II

HONG KONG EXAMINATIONS AUTHORITY
HONG KONG CERTIFICATE OF EDUCATION EXAMINATION 2001
PHYSICS PAPER 2
10.45 am-11.45 am (1 hour)
Subject Code 170
1.
Read carefully the instructions on the Answer Sheet and insert the information
required (including the Subject Code) in the spaces provided.
2.
When told to open this book, you should check that all the questions are there. Look
for the words 'END OF PAPER' after the last question.
3.
All questions carry equal marks.
4.
ANSWER ALL QUESTIONS. You should mark all your answers on the Answer
Sheet.
5.
You should mark only ONE answer for each question. If you mark more than one
answer, you will receive NO MARKS for that question.
6.
No marks will be deducted for wrong answers.
2001-CE-PHY II - 1
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There are 45 questions. The last page of this question paper contains a list of physics
formulae which you may find useful.
If necessary, take g = 10 m s-2
Unless otherwise specified, all the cells are assumed to have
negligible internal resistance.
(2001-CE-PHY II - 1)
1.
A car travels along a straight road. The variation of the distance of the car
from a fixed point P on the road with time is shown above. Which of the
following statements is correct ?
A.
B.
C.
D.
E.
The speed of the car is decreasing.
The car is moving towards P.
There is an unbalanced force acting on the car.
The area under the graph denotes the total distance travelled by the
car.
The slope of the graph denotes the acceleration of the car.
(2001-CE-PHY II - 2)
2. A girl walks along a straight road from a point A to a point B with an average
speed 1 m s-1. She then returns from B to A along the same road with an
average speed 2 m s-1. Find the average speed of the girl for the whole
journey.
A.
B.
C.
D.
E.
zero
0.67 m s-1
1.33 m s-1
1.41 m s-1
1.50 m s-1
2001-CE-PHY II - 2
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(2001-CE-PHY II - 3)
3.
A stone is thrown vertically upwards. Assuming air resistance is negligible,
which of the following statements is/are correct ?
(1)
(2)
(3)
The acceleration of the stone decreases throughout the upward motion.
The net force acting on the stone becomes zero when the stone reaches
the highest point.
The total energy of the stone remains unchanged throughout the motion.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2001-CE-PHY II - 4)
4.
A coin is placed on a piece of cardboard resting on a glass as shown above. If
the cardboard is flicked off sharply with a finger, the coin will drop into the
glass. What does this experiment demonstrate ?
A.
B.
C.
D.
E.
The coin will fall with uniform acceleration under the action of
gravity.
The acceleration of the coin is proportional to the applied force.
Action and reaction always occur in pairs.
Momentum is conserved in a collision.
The coin has a tendency to maintain its state of rest.
2001-CE-PHY II - 3
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(2001-CE-PHY II - 5)
5.
A block on a rough horizontal table is acted on by two horizontal forces of
magnitudes 10 N and 2 N as shown. It remains at rest on the table. If the force
of magnitude 10 N is removed, find the resultant force acting on the block.
A.
B.
C.
D.
E.
zero
2N
6N
8N
10 N
(2001-CE-PHY II - 6)
6.
A uniform plank of weight 450 N rests on two trestles X and Y and a worker
of weight 675 N stands at one end of the plank as shown above. The worker
holds a light basket which contains several packets of goods each of weight
6 N. What is the maximum number of packets he can hold without tilting the
plank ? (Assume the weight of the plank acts through its centre.)
A.
B.
C.
D.
E.
11
12
13
18
19
2001-CE-PHY II - 4
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(2001-CE-PHY II - 7)
7.
A student uses a friction-compensated runway to study Newton’s second law
of motion. The variation of the acceleration a of the trolley with the force F
applied parallel to the runway is shown above. If the experiment is repeated
with the runway making a larger angle of inclination with the horizontal,
which of the following graphs (in dotted lines) represents the expected result ?
A.
B.
C.
D.
E.
2001-CE-PHY II - 5
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(2001-CE-PHY II - 8)
8.
The figure above shows the variation of the force acting on a car driver with
time when the car hits a wall. The driver is not wearing a seat-belt. Which of
the following graphs (in dotted lines) best shows the force acting on the
deriver if he is wearing a seat-belt ?
A.
B.
C.
D.
E.
2001-CE-PHY II - 6
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(For questions 9 and 10.) A man is pulling a suitcase along the horizontal ground
as shown below.
(2001-CE-PHY II - 9)
9. Which of the following pairs of forces is/are action and reaction pair(s)
according to Newton’s third law of motion ?
The
gravitational
force
The gravitational force exerted
(1)
exerted by the man on the
and
by the earth on the man
earth
The pulling force exerted by
The friction exerted by the
(2)
and
the man on the suitcase
ground on the suitcase
The normal reaction exerted
The gravitational force exerted
(3)
by the ground on the
and
by the earth on the suitcase
suitcase
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
E. (1), (2) and (3)
(2001-CE-PHY II - 10)
10. If the rope is inclined at angle θ to the horizontal and the tension in the rope
is 100 N, find the work done by the man in pulling the suitcase for a distance
of 5 m along the ground.
A.
B.
C.
D.
E.
500 J
500 sinθJ
500 cosθJ
500
J
sin 
500
J
cos 
2001-CE-PHY II - 7
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(2001-CE-PHY II - 11)
11. A rocket of mass 5000 kg is at rest in space. It then explodes and breaks into
two parts P1 and P2 of mass 1000 kg and 4000 kg respectively. Find the ratio
of the kinetic energy of P1 to that of P2.
A. 1 : 1
B. 1 : 16
C. 1 : 64
D. 4 : 1
E. 16 : 1
(2001-CE-PHY II - 12)
12.
The figure above shows a nail being driven into a wooden door with a
hammer. Which of the following statements is/are correct ?
(1)
(2)
(3)
Using a hammer can reduce the work done against the resistance on the
nail by the door.
The force exerted by the nail on the door is larger than that exerted by
the hammer on the nail.
The pressure exerted by the nail on the door is larger than that exerted by
the hammer on the nail.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2001-CE-PHY II - 8
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(2001-CE-PHY II - 13)
13. Which of the following images in the photographs is/are virtual ?
(1)
the image on the screen in a
cinema
(3) the image on the surface of a
pool of calm water
2001-CE-PHY II - 9
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(2) the image in a security
mirror in a supermarket
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2001-CE-PHY II - 14)
14.
Two parallel rays from a distant object strike a concave mirror as shown
above, where F is the focus. At which of the following points does the
image of the object form ?
A.
B.
C.
D.
E.
P
Q
R
S
T
2001-CE-PHY II - 10
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(2001-CE-PHY II - 15)
15.
An object is placed in front of a curved mirror and an image is formed as
shown above. Which of the following describes the type of mirror being used
and the nature of the image formed ?
Mirror
convex
convex
concave
concave
concave
A.
B.
C.
D.
E.
Image
real and formed in front of the mirror
virtual and formed behind the mirror
real and formed in front of the mirror
real and formed behind the mirror
virtual and formed behind the mirror
(2001-CE-PHY II - 16)
16. A melting ice block of mass 0.05 kg is mixed with x kg of water at 0℃ in a
well-insulated container. If 25 000 J of energy is supplied to the mixture, the
mixture changes to water at 4℃. Find the value of x.
(Given : specific latent heat of fusion of ice = 3.34 x 105 Jkg-1,
specific heat capacity of water = 4200 J kg-1 K-1.)
A.
B.
C.
D.
E.
0.37
0.44
0.49
1.44
1.49
2001-CE-PHY II - 11
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(2001-CE-PHY II - 17)
17.
The above apparatus is used to measure the specific heat capacity of a
cylindrical copper block. The result of the experiment is as follows:
Mass of copper block
Initial temperature
Final temperature
Initial joulemeter reading
Final joulemeter reading
= m kg
= 21℃
= 47℃
= R1 J
= R2 J
Which of the following expressions gives the specific heat capacity of copper
( in J kg-1 K-1) ?
A.
B.
C.
D.
E.
26m( R2  R1 )
R1  R2
26m
R2  R1
26m
m( R1  R2 )
26
m( R2  R1 )
26
2001-CE-PHY II - 12
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(2001-CE-PHY II - 18)
18.
The figure above shows the cooling curve of a substance which is initially in
the liquid state. The temperature of the substance remains unchanged during
the period PQ. Which of the following statements about the substance during
the period PQ is/are correct ?
(1)
(2)
(3)
The substance is not losing any energy to the surroundings.
Latent heat is absorbed by the substance.
The average potential energy of the molecules of the substance is
decreasing.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2001-CE-PHY II - 19)
19. A cup of liquid P and a cup of liquid Q of equal mass are heated at the same
rate. It is found that the temperature of P is rising at a rate faster than that of Q.
Which of the following deduction is/are correct ?
(1)
(2)
(3)
P has a lower specific latent heat of vaporization than Q
P has a lower boiling point than Q.
P has a lower specific heat capacity than Q.
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
E. (1), (2) and (3)
2001-CE-PHY II - 13
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(2001-CE-PHY II - 20)
20.
The above apparatus is used to study the relation between the pressure and
temperature of a fixed mass of gas at constant volume. Which of the following
can improve the accuracy of the experiment ?
(1)
(2)
(3)
using a larger flask
using a shorter length of rubber tubing to connect the gauge and the flask
setting up a control experiment with the burner removed
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2001-CE-PHY II - 14
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(2001-CE-PHY II - 21)
21.
The above graph shows the V-T relation of a fixed mass of ideal gas. Point X
denotes the initial state of the gas. The gas changes its state from X to Y,
then from Y to Z and finally from Z back to X along the path shown. Which of
the following statements about the pressure of the gas is/are correct ?
(1)
(2)
(3)
The pressure remains unchanged in the transition from X to Y.
The pressure increases in the transition from Y to Z.
The pressure decreases in the transition from Z to X.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2001-CE-PHY II - 22)
22. Which of the following is not a transverse wave ?
A.
B.
C.
D.
E.
radio waves
visible light
ultra-violet
X-rays
ultrasonic waves
2001-CE-PHY II - 15
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(2001-CE-PHY II - 23)
23.
Five corks are moving up and down on the surface of a pond as a water
wave passes through them. At time t = 0, the positions of the corks are
shown above. The figure below shows the displacement-time graph of
one of the five corks. Which cork has the motion represented by the graph ?
(Note : Displacement is positive when the cork is above the still water
surface.)
A.
B.
C.
D.
E.
P
Q
R
S
T
(2001-CE-PHY II - 24)
24. A sonar on a ship is used to find the depth of the sea. An ultrasonic wave pulse
is sent downwards from the ship towards the sea bed. The pulse travels with a
speed of 1500 m s-1 in sea water. If the reflected pulse is received after 0.16 s,
find the depth of the sea.
A.
B.
C.
D.
E.
120 m
240 m
480 m
4688 m
9375 m
2001-CE-PHY II - 16
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(2001-CE-PHY II - 25)
25.
In the above diagram, XY represents a boundary between a deep region and a
shallow region of water in a ripple tank. A serried of straight water waves in
the deep region travels towards XY. Which of the following diagrams best
shows the wave pattern in the shallow region ?
2001-CE-PHY II - 17
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(2001-CE-PHY II - 26)
26.
Water waves of
wavelength
λ
are
diffracted as they pass through a gap of width d as shown above. Which of the
following changes would produce the most significant diffraction effect ?
λ
A.
B.
C.
D.
E.
d
remains unchanged
remains unchanged
halved
halved
halved
halved
doubled
halved
remains unchanged
doubled
(2001-CE-PHY II - 27)
27. Which of the following relations is incorrect ?
A.
B.
C.
D.
E.
1 pascal (Pa)
1 watt (W)
1 coulomb (C)
1 volt (V)
1 ohm (Ω)
2001-CE-PHY II - 18
=
=
=
=
=
1 newton per metre squared (N m-2)
1 joule per second (J s-1)
1 ampere per second (A s-1)
1 joule per coulomb (J C-1)
1 volt per ampere (V A-1)
-18-
(2001-CE-PHY II - 28)
28.
Two charged spheres A and B are hanging at a point on a ceiling by two
identical nylon threads. They remain at rest as shown above. Which of the
following statements must be correct ?
(1)
(2)
(3)
Both spheres carry positive charges.
The force acting on B by A is larger than the force acting on A by B.
The mass of A is larger than B.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2001-CE-PHY II - 29)
29.
If the ammeter in the above circuit reads 3 A, find the voltage of the battery.
A.
B.
C.
D.
E.
11 V
12 V
13.5 V
15 V
18 V
2001-CE-PHY II - 19
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(2001-CE-PHY II - 30)
30.
In the above circuit, the two resistors are identical. If switch S is closed,
which of the following predictions is incorrect ?
A.
B.
C.
D.
E.
The reading of the ammeter A1 increases.
The reading of the ammeter A2 remains unchanged.
The reading of the voltmeter remains unchanged.
The power delivered by the battery increases.
The potential difference between points X and Y increases.
(2001-CE-PHY II - 31)
31. Which of the following diagrams shows the correct connection of the fuse and
switch of an electric kettle to the mains supply ?
(L : live, N : neutral, E : earth)
A.
C.
E.
2001-CE-PHY II - 20
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(2001-CE-PHY II - 32)
32. Two electrical heaters X and Y are of ratings ‘110 V, 40 W’ and ‘110V, 80 W’
respectively. Which of the following deductions about the two heaters is/are
correct ?
(1)
(2)
(3)
The operating resistance of X is twice that of Y.
X will consume a power of 80 W when it is connected to a 220 V mains
supply.
Both heaters work at their rated values when they are connected in series
to a 220 V mains supply.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2001-CE-PHY II - 33)
33.
Figure (a)
Figure (b)
Figure (a) shows the trace of a signal on a CRO. In order to change the trace
of the signal into the form shown in Figure (b), which of the following
settings of the CRO should be adjusted ?
A.
B.
C.
D.
E.
Y-gain only
Y-shift only
time base only
Y-gain and Y-shift
Y-gain and time base
2001-CE-PHY II - 21
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(2001-CE-PHY II - 34)
34.
A 12 V a.c. supply is connected to a transformer with turns ratio 1 : 1. The
secondary coil is tapped at equal intervals as shown above. Two ‘6 V, 0.5 W’
light bulbs are connected to the secondary coil of the transformer. In which of
the following cases will the two bulbs work at their rated values ?
(1)
(2)
(3)
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2001-CE-PHY II - 22
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(2001-CE-PHY II - 35)
35.
A long solenoid is placed in a vertical position and its two ends are
connected to the Y-input of a CRO (with the time base switched on). A bar
magnet is released above the solenoid so that it falls through the solenoid.
Which of the following best represents the trace shown on the CRO ?
A.
B.
C.
D.
E.
2001-CE-PHY II - 23
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(2001-CE-PHY II - 36)
36.
The figure above shows an electromagnet which is used to pick up iron
objects. Which of the following can increase the strength of the
electromagnet ?
(1) increasing the number of turns of the coil
(2) reducing the resistance of the variable resistor
(3) replacing the battery with a 12 V a.c. power supply
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
E. (1), (2) and (3)
(2001-CE-PHY II - 37)
37.
The above diagram shows a combination of two NAND gates. Which of the
following sets of inputs would give a high output at S ? (Take 1 for high
voltage and 0 for low voltage.)
P
Q
R
(1)
1
1
1
(2)
1
0
0
(3)
0
0
0
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2001-CE-PHY II - 24
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(2001-CE-PHY II - 38)
38.
The figure above shows an incomplete circuit. A student uses a resistor, a
switch and a light dependent resistor (LDR) to complete the circuit, so that the
buzzer will sound only when the switch is pressed and the LDR is illuminated.
Which of the following correctly shows the position of the three components ?
X
A.
B.
C.
D.
E.
switch
resistor
resistor
LDR
LDR
Y
Z
LDR
LDR
switch
resistor
switch
resistor
switch
LDR
switch
resistor
(2001-CE-PHY II - 39)
226
Ra ) decays by emitting an αparticle to form a product nucleus
39. Radium ( 88
X. Which of the following shows the correct equation for this decay ?
A.
226
88
Ra    222
86 X
B.
226
88
Ra    230
90 X
C.
226
88
Ra  224
84 X  
D.
226
88
Ra  222
86 X  
E.
226
88
Ra  226
89 X  
2001-CE-PHY II - 25
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(2001-CE-PHY II - 40)
40. The initial activity of a radioactive isotope is 2000 distintegrations per second.
After 4 hours, the activity of the isoptope drops to 125 disintegrations per
second. Find the half-life of the isotope.
A.
B.
C.
D.
E.
15 minutes
30 minutes
48 minutes
60 minutes
80 minutes
(2001-CE-PHY II - 41)
41.
The above shows part of a radioactive series. Which of the following nuclei
are isotopes of the same element ?
A.
B.
C.
D.
E.
P and Q
P and R
P and S
Q and S
Q, R and S
2001-CE-PHY II - 26
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Directions : Each question below (Questions 41-45) consists of two statements. Decide
whether each of the two statements is true or false. If both are true, then
decide whether or not the second statement is a correct explanation of the first
statement. Then select one option A-E according to the following table :
1st statement
2nd statement
A.
True
True
B.
True
True
C.
D.
E.
True
False
False
False
True
False
2nd statement is a correct explanation of
the 1st statement
2nd statement is not a correct explanation
of the 1st statement
1st statement
(2001-CE-PHY II - 42)
42.
The efficiency of using a
screwjack to raise a car can be
improved by increasing the
length of the handle of the
screwjack.
(2001-CE-PHY II - 43)
43.
When a lens is used as a
magnifying glass to look on a
small object, the image formed
is real.
(2001-CE-PHY II - 44)
44.
The speed of gamma rays in air
is much higher than that of
visible light.
(2001-CE-PHY II - 45)
45.
In examining foetuses (babies
not yet born), ultrasonics are
used but not X-rays.
2001-CE-PHY II - 27
2nd statement
Increasing the length of the
handle of the screwjack can
reduce the effort required to
raise the car.
When a lens is used as a
magnifying glass, the object
and the image formed are on
different sides of the lens.
Gamma rays can pass through
aluminium sheets of a few
mm thick but visible light
cannot.
X-rays will cause damage to
human
cells
whereas
ultrasonics will not.
END OF PAPER
-27-
Useful Formulae in Physics
(a)
Relationships between initial velocity u, constant acceleration a, final velocity y and
distance travelled s after time t :
v  u  at
1
s  ut  at 2
2
v 2  u 2  2as
(b)
Potential energy gained by a body of mass m when raised through a height h is mgh .
(c)
Kinetic energy of a body of mass m moving with speed v is
(d)
Power = force x velocity
(e)
Equivalent resistance of two resistors R1 and R2 :
(f)
(i)
in series = R1 + R2
(ii)
in parallel
=
R1 R2
R1  R2
Power = potential difference x current
2001-CE-PHY II - 28
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1 2
mv .
2
2001 Physics Paper 2
Question No.
Key
Question No.
Key
1.
2.
3.
4.
5.
B
C
B
E
A
26.
27.
28.
29.
30.
A
C
B
A
E
6.
7.
8.
9.
10.
B
C
C
A
C
31.
72.
33.
34.
35
D
A
D
E
A
11.
12.
13
14.
15.
D
B
D
B
E
36.
37.
38
39.
40.
C
E
D
D
D
16.
17.
18.
19.
20
B
C
B
B
C
41.
42.
43.
44.
45.
C
D
E
D
A
21.
22.
23.
24.
25.
E
E
B
A
A
2001-CE-PHY II - 29
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