Download 2000-CE-PHY II

HONG KONG EXAMINATIONS AUTHORITY
HONG KONG CERTIFICATE OF EDUCATION EXAMINATION 2000
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, check that all the questions are there. Look
for the words 'END OF PAPER' after the last question.
3.
ANSWER ALL QUESTIONS. All the answers should be marked on the
Answer Sheet.
4.
Note that you may only mark ONE answer to each question. Two or
more answers will score NO MARKS.
5.
All questions carry equal marks. No marks will be deducted for wrong
answers.
2000-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.
(2000-CE-PHY II - 1)
1.
Which of the following physical quantities is not a vector ?
A.
B.
C.
D.
E.
acceleration
displacement
momentum
potential energy
weight
(2000-CE-PHY II - 2)
2. It is said that Galileo Galilei (1564-1642), an Italian scientist, dropped a
small iron ball and a large cannon ball from the top of the Leaning Tower
of Pisa. He found that the two balls reached the ground at almost the same
time.
Which of the following is/are correct deduction(s) from this experiment ?
(1)
(2)
(3)
The two balls fell with the same acceleration.
A body will maintain uniform motion if there is no external force
acting on it.
The gravitational forces acting on the two balls were identical.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2000-CE-PHY II - 2
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(2000-CE-PHY II - 3)
3.
A racing car accelerates from rest to a speed of 100 km h -1 in 3.2 s. Find
the average acceleration of the car.
A.
B.
C.
D.
E.
4.34 m s-2
8.68 m s-2
15.63 m s-2
31.25 m s-2
112.50 m s-2
(2000-CE-PHY II - 4)
4.
The cars A and B travel along the same straight road. The velocity-time
graphs of the two cars are shown above. Which of the following
statements about the motion of the two cars at time T0 is/are always
correct ?
(1)
(2)
(3)
The two cars meet each other.
The two cars are moving with the same speed but in opposite
directions.
Car A is accelerating while B is decelerating.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2000-CE-PHY II - 3
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(2000-CE-PHY II - 5)
5.
An astronaut lands on the moon and finds that his weight is about
one-sixth of that on earth. Which of the following deductions is/are
correct ?
(1)
(2)
(3)
If he throws an object upwards on the moon, it will reach a higher
level than throwing the object with the same speed on earth.
If he releases an object on the moon, it will take a shorter time to
reach the ground than releasing the object from the same height on
earth.
The maximum weight he can lift on the moon is greater than on
earth.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2000-CE-PHY II - 6)
6.
Three forces of magnitudes F1, F2 and 10 N act on an object as shown
above. If the object is in equilibrium, find F2.
A.
B.
C.
D.
E.
5.0 N
8.7 N
11.5 N
17.3 N
20.0 N
2000-CE-PHY II - 4
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(2000-CE-PHY II - 7)
7.
A block is placed on a rough inclined plane and then projected upwards
along the plane. After reaching the highest point, the block slides down
along the plane. Which of the following graphs shows the variation of the
velocity v of the block with time t ?
A.
B.
C.
D.
E.
2000-CE-PHY II - 5
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(2000-CE-PHY II - 8)
8.
A uniform steel ball lies at rest on a horizontal ground and just touches a
vertical wall as shown above. Which of the following diagrams shows all
the forces acting on the ball ?
(Note : W = gravitational force acting on the ball,
R = normal reaction from the ground,
F = friction acting by the ground on the ball,
N = normal reaction from the wall.)
A.
B.
C.
D.
E.
2000-CE-PHY II - 6
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(2000-CE-PHY II - 9)
9.
A block is placed on a rough horizontal ground and a horizontal force acts
on the block. If the magnitude of the force, F, is increased gradually,
which of the following graphs shows the relation between F and the
acceleration a of the block ?
A.
B.
C.
D.
E.
2000-CE-PHY II - 7
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(2000-CE-PHY II - 10)
10.
The above graph shows the variation of the kinetic energy E of an object
with the square of its velocity v2. What is the momentum of the object
when it is moving at a velocity 4 m s-1 ?
4 kg ms-1
8 kg ms-1
16 kg ms-1
32 kg ms-1
It cannot be determined since the mass of the object is not
given.
(2000-CE-PHY II - 11)
11.
A.
B.
C.
D.
E.
A 2 kg block is initially at rest on the ground. A machine is used to pull up
the block as shown above. If the tension in the string is kept at 24 N and
the block reaches a height of 4 m in 2 s, which of the following statements
is/are correct ?
(1)
(2)
(3)
The potential energy of the block is increasing when the block is
rising.
The kinetic energy of the block is increasing when the block is
rising.
The average power developed by the machine during the two
seconds is 40 W.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2000-CE-PHY II - 8
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(2000-CE-PHY II - 12)
12.
A company intends to produce a kind of weighing device as shown above.
The device is held at point X. The position of the counter-weight is
adjusted until the rod AB becomes horizontal. The weight of the object can
be read form the scale calibrated on AB. Which of the following changes
can increases the maximum weight that can be measured by the device ?
(1)
(2)
(3)
moving the string at X towards A
increasing the mass of the counter-weight
increasing the length of the string from which the counter-weight
hangs
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2000-CE-PHY II - 9
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(2000-CE-PHY II - 13)
13. Which of the following optical devices can be used to focus sunlight on a
match and set it on fire ?
(1)
(2)
(3)
a magnifying glass
the parabolic mirror of an electric torch
a spectacle lens used for correcting long-sightedness
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2000-CE-PHY II - 14)
14.
An object is placed in front of a mirror M and an image is formed as
shown above. What type of mirror is M and what is its focal length ?
A.
B.
C.
D.
E.
Type of mirror
convex
convex
concave
concave
concave
2000-CE-PHY II - 10
Focal length
20 cm
40 cm
20 cm
40 cm
80 cm
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(2000-CE-PHY II - 15)
15.
F and F` are the foci of the above lens and AB is an incident ray. Which of
the following paths best represents the emergent ray ?
A.
B.
C.
D.
E.
P
Q
R
S
T
(2000-CE-PHY II - 16)
16.
A ray of light enters a glass prism and travels along the path as shown
above. Find the refractive index of the glass.
A.
B.
C.
D.
E.
0.68
1.07
1.37
1.47
1.50
2000-CE-PHY II - 11
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(2000-CE-PHY II - 17)
17.
A student uses a single-lens camera to take a photograph of two books.
The photograph turns out to be blurred as shown in Figure (a). Which of
the following changes can enable the student to take a sharp photograph of
the books at the same location (see Figure (b)) ?
(1)
(2)
(3)
using a flash in taking the photograph
replacing the lens of the camera by another one of longer focal
length
adjusting the distance between the lens and the film
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2000-CE-PHY II - 12
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(2000-CE-PHY II - 18)
18.
A student uses two triangular prisms to construct a periscope as shown
above. Which of the following shows the image of the object as seen by
the observer ?
A.
B.
C.
D.
E.
(2000-CE-PHY II - 19)
19. A cup of fruit juice is of mass 0.2 kg and temperature 70℃. If the specific
heat capacity of the fruit juice is 4000 Jkg-1K-1, find the minimum amount
of ice at 0℃ that should be added to the juice in order to lower its
temperature to 0℃.
(Note : Specific latent heat of fusion of ice = 3.34 x 105 J kg-1.)
A.
B.
C.
D.
E.
0.17 kg
0.20 kg
0.37 kg
0.84 kg
4.19 kg
2000-CE-PHY II - 13
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(2000-CE-PHY II - 20)
20. Equal masses of five different liquids are separately heated at the same
rate. The initial temperatures of the liquids are all 20℃. The boiling points
and specific heat capacities of the liquids are shown below. Which one of
them will boil first ?
Liquid
A.
B.
C.
D.
E.
P
Q
R
S
T
Boiling point/
℃
50
60
80
80
360
Specific heat capacity/ J
kg-1K-1
1000
530
850
1710
140
(2000-CE-PHY II - 21)
21.
The above apparatus is used to find the specific latent heat of vaporization
of water lv. Which of the following factors will cause the result obtained to
be larger than the true value of lv ?
(1)
(2)
(3)
Some energy is lost to the surroundings.
Some steam condenses and drips back into the beaker.
Some boiling water inside the beaker splashes out of the beaker.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2000-CE-PHY II - 14
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(2000-CE-PHY II - 22)
22. An object P has a higher temperature than another object Q. Which of the
following statements is/are correct ?
(1)
(2)
(3)
The internal energy of P must be higher than that of Q.
The specific heat capacity of P must be higher than that of Q.
There will be a heat flow from P to Q when they are in contact.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2000-CE-PHY II - 23)
23.
The curve C in the above graph shows the P-V relation of a fixed mass of
ideal gas at a certain temperature. Point X denotes the initial state of the
gas. The state of the gas is now changed along the path shown from X to Y,
then from Y to Z, and finally from Z back to X along the curve C. Which of
the following statements is/are correct ?
(1)
(2)
(3)
The temperature of the gas remains unchanged in the transition from
X to Y.
The temperature of the gas decreases in the transition from Y to Z.
The temperature of the gas remains unchanged 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)
2000-CE-PHY II - 15
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(2000-CE-PHY II - 24)
24. Which of the following statements correctly describe(s) the meaning of the
frequency of a wave ?
(1)
(2)
(3)
the time taken for the wave to make one complete vibration
the distance travelled by the wave in one second
the number of waves produced in one second
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2000-CE-PHY II - 25)
25. Scientists have discovered that ozone molecules in the earth’s atmosphere
are being destroyed. Which of the following electromagnetic waves is
mainly responsible for causing hazard to human health as a result of the
damaging of the ozone layer?
A.
B.
C.
D.
E.
gamma radiation
visible light
infra-red
microwaves
ultra-violet
(2000-CE-PHY II - 26)
26. A water wave of frequency 30 Hz travels in a deep region of water. When
the wave enters a shallow region, its wavelength is reduced to one-third of
its original value. Find the frequency of the water wave in the shallow
region.
A.
B.
C.
D.
E.
10 Hz
30 Hz
60 Hz
90 Hz
It cannot be determined since the speed of the water wave is
not given.
2000-CE-PHY II - 16
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(2000-CE-PHY II - 27)
27.
A straight pulse PQ travels towards a V-shaped barrier in ripple tank as
shown above. Which of the following diagrams best shows the reflected
pulse(s) ?
A.
B.
C.
D.
E.
2000-CE-PHY II - 17
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(2000-CE-PHY II - 28)
28.
A microphone and a CRO are used to detect the sound emitted by two
tuning forks X and Y in turn. The figure above shows the traces obtained,
with the setting of the CRO unchanged. Find the ratio of the frequency of
the sounds emitted by X to that of Y.
A.
B.
C.
D.
E.
1:2
2:1
2:3
4:5
5:4
(2000-CE-PHY II - 29)
29.
Two insulated uncharged metal spheres X and Y are placed in contact. A
positively-charged rod is brought near X as shown above. X is then earthed
momentarily. The charged rod is removed and the two spheres are then
separated. Which of the following describes the charges on X and Y ?
A.
B.
C.
D.
E.
2000-CE-PHY II - 18
Sphere X
Sphere Y
negative
negative
positive
uncharged
uncharged
negative
uncharged
positive
uncharged
positive
-18-
(2000-CE-PHY II - 30)
30.
Three resistors are connected to a battery as shown above. Which of the
following statements is/are correct ?
(1)
(2)
(3)
The current passing through R1 is equal to that passing through R2.
The potential difference across R1 is equal to that across R2.
The energy dissipated by a coulomb of charge passing through the
4Ω-resistor is equal to that dissipated by a coulomb of charge
passing through PQ.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
(2000-CE-PHY II - 31)
31.
The switch S in the above circuit is closed, which of the following
statements is/are correct ?
(1)
(2)
(3)
The readings of ammeters A1 and A2 are both increased.
The ratio of the readings of ammeters A1 to A2 is increased.
The reading of ammeter A3 remains unchanged.
A.
B.
C.
D.
E.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2000-CE-PHY II - 19
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(2000-CE-PHY II - 32)
32.
In the above circuit, D1, D2 are diodes of negligible resistance and P, Q are
identical bulbs. Which of the bulbs will light up when
(1)
(2)
switch S is open, and
S is closed ?
A.
B.
C.
D.
E.
S is open
S is closed
P
Q
P and Q
P and Q
P and Q will not light up
Q
P and Q will not light up
P and Q
P and Q will not light up
P and Q
(2000-CE-PHY II - 33)
33. A moving coil milliammeter has a resistance of 10Ω and a full-scale
deflection of 0.01A. It is converted into an ammeter with a full-scale
deflection of 1.0A by connecting a resistor R to it. Which of the following
shows the resistance of R and the method of connection ?
Resistance of R
A.
B.
C.
D.
E.
2000-CE-PHY II - 20
0.1Ω
0.1Ω
1Ω
90Ω
90Ω
Method of connecting R
and the milliammeter
in parallel
in series
in parallel
in parallel
in series
-20-
(2000-CE-PHY II - 34)
34.
A resistor and a bulb are connected in parallel to a 9 V battery as shown
above. The reading of the ammeter is 5 A. If the power dissipated by the
resistor is 18 W, find the power dissipated by the bulb.
A.
B.
C.
D.
E.
9W
18 W
22.5 W
27 W
45 W
(2000-CE-PHY II - 35)
35.
The above diagram shows the main parts of an electric iron. In which of
the following situations will the fuse blow when the switch is closed ?
(1)
(2)
(3)
The insulation at contact point
touches the metal case.
The insulation at contact point
touches the metal case.
The heating element is broken.
A.
B.
C.
D.
E.
X is worn out so that the wire
Y is worn out so that the wire
(1) only
(3) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
2000-CE-PHY II - 21
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(2000-CE-PHY II - 36)
36.
The above diagram shows an experimental set-up for measuring the
resistance of a bulb. To which of the terminals P, Q and R of the ammeter
and voltmeter should each of the wires be connected ?
A.
B.
C.
D.
E.
2000-CE-PHY II - 22
Wire (1)
Wire (2)
Wire (3)
P
P
Q
R
R
Q
R
P
P
Q
R
Q
R
Q
P
-22-
(2000-CE-PHY II - 37)
37.
The above circuit is used to control the operation of a motor. Under which
of the following conditions will the motor be turned on ?
A.
B.
C.
D.
E.
Switch S is closed or the temperature of X is low.
Switch S is open or the temperature of X is high.
Switch S is closed and the temperature of X is low.
Switch S is closed and the temperature of X is high.
Switch S is open and the temperature of X is low.
(2000-CE-PHY II - 38)
38. A bar magnet is placed near a solenoid. Which of the following correctly
shows the direction of the induced current in the solenoid ?
(Note : The arrow”
or solenoid.)
“ indicates the direction of motion of the magnet
A.
B.
C.
D.
E.
2000-CE-PHY II - 23
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(2000-CE-PHY II - 39)
39.
Figure (a) shows the display on a CRO with no signal applied to the
Y-input and the time base switched on. The Y-input of the CRO is then
connected to a circuit as shown in Figure (b). Which of the following
shows the display on the CRO when
(1) switch S is closed, and
(2) switch S is open ?
S is closed
S is open
A.
B.
C.
D.
E.
2000-CE-PHY II - 24
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(2000-CE-PHY II - 40)
40. Which of the following statements aboutαparticles andγrays is correct ?
A.
B.
C.
D.
E.
Both of them carry charges.
Both of them are transverse waves.
Both of them can be deflected by a magnetic field.
Both of them have strong ionizing power.
Both of them can travel through a vacuum.
(2000-CE-PHY II - 41)
41. Which one of the following is not a safety precaution for handling
radioactive sources ?
A.
B.
C.
D.
E.
Radioactive sources should be handled with forceps.
Users should not eat or drink when handling radioactive
sources.
Users should wash their hands after handling radioactive
sources.
Radioactive sources should not be held close to the eye for
visual examination.
Radioactive sources should be stored in wooden boxes after
use.
2000-CE-PHY II - 25
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Directions : Each question below (Questions 42-45) 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
2nd statement
(2000-CE-PHY II - 42)
42. When one of a pair of action and
reaction forces is removed, the
other force will also disappear.
(2000-CE-PHY II - 43)
43. Without a screen, a real image
cannot be seen by an observer..
(2000-CE-PHY II - 44)
44. If an a.c. supply is connected to a
resistor, no internal energy will be
dissipated by the resistor.
(2000-CE-PHY II - 45)
45. α sources are not suitable for
injection into human bodies as
medical tracers.
A pair of action and reaction forces
acts on the same body.
The image of an object formed on
a screen is always real.
If an a.c. supply is connected to a
resistor, the direction of current
flowing through the resistor will
change with time.
α particles carry positive charges
and can be deflected by electric
fields.
END OF PAPER
2000-CE-PHY II - 26
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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
2000-CE-PHY II - 27
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1 2
mv .
2
2000 Physics Paper II
Question No.
Key
Question No.
Key
1.
2.
3.
4.
5.
D
A
B
B
A
26.
27.
28.
29.
30.
B
E
D
A
D
6.
7.
8.
9.
10.
C
E
B
E
C
31.
32.
33.
34.
35
A
D
A
D
A
11.
12.
13
14.
15.
C
C
E
D
E
36.
37.
38
39.
40.
A
C
C
C
E
16.
17.
18.
19.
20
D
B
A
A
B
41.
42.
43.
44.
45.
E
C
D
D
B
21.
22.
23.
24.
25.
C
B
D
B
E
2000-CE-PHY II - 28
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