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CCC Hoh Fuk Tong College
Mock Examination 2009 – 2010
Physics Paper II
Secondary : 7
Time allowed : 3 hours ( 1:45 p.m. - 4:45 p.m.)
Name : ______________________________
Date : 3 / 3 / 2010
Marks : 93
Class : S. 7S
Number : ______
Section A : Answer ALL questions.
Section B : Answer Any THREE questions.
Instructions for Section A
1. You should use an HB pencil to mark all your answers on the Answer Sheet.
Wrong marks must be completely erased.
2. You should mark only ONE answer for each question in Section A. If you mark
more than one answer, you will receive NO MARKS for that question.
3. No marks will be deducted for wrong answers in Section A.
Section A
There are 45 questions in this section. Each question is followed by four suggested
answers. Where necessary, take the acceleration due to gravity to be 10 m s -2 and take
the speed of light in air to be 3 x 108 m s-1.
1.
Q
30o
R
P
X
A uniform metre rule of mass 0.2 kg is hinged to a wall at P and the other end R
is connected by a wire attached to the wall at Q, vertically above P as shown in
the diagram above. A block X of mass 0.1 kg is hung from the rule 25 cm from R.
The metre rule is horizontal. Find the tension in the wire.
A. 1.5 N
B. 3.5 N
C. 4.0 N
2
D. 7.0 N
2. A particle of mass m, traveling at speed u, strikes a stationary particle of
mass 2m. As a result, the particle of mass m is deflected through 60o and has
a final speed of u/2. The speed of the particle of mass 2m after this collision
will be
A. u/4
B. u/2
C. (0.433) u
D. (0.217) u
3.
A small ball is projected from A with 3 ms-1 at 30 with horizontal. The ball
hits the wall at B that is at the same horizontal level as A. Calculate the
distance AB.
A
A.
B.
C.
D.
4.
0.45 m
0.78 m
0.90 m
1.80 m
A particle X moving with kinetic energy E and momentum p makes a head-on
collision with an identical particle Y which is initially at rest. Two particles
stick together after collision. Which of the following correctly represents the
kinetic energy and momentum of X after the collision?
A.
B.
C.
D.
5.
B
30
kinetic energy
0
E/2
E/4
E/4
momentum
p
p/2
p/2
p/4
An object of mass 8.0 kg is tied to one end of a string and whirled around in a
vertical circle of radius 2.0 m. At the top of the circular path, the speed of the
object is found to be 5.0 ms-1. The tension of the string at this position is
A.
B.
C.
D.
0N
20 N
100 N
180 N
3
D
6.
H
E
C
I
A
B
G
F
J
ABCDEFGHIJ is a smooth metal rail bent in such a way that BCDE and FGHI
are two circles of radii 1.2 m and 0.8 m respectively. A, B, F and J are on the
same horizontal level. A small marble is projected at A so that the reaction
force acting on the marble at D is zero. Which of the following statements is
INCORRECT ?
A.
B.
C.
D.
7.
The centripetal force on the marble at D equals to its weight.
The centripetal force on the marble at D is smaller than that at B.
The centripetal force on the marble at F is greater than that at B.
The marble will loss contact with the rail somewhere between G and H.
Satellite A is observed to revolve the earth once in 2 days, while another satellite
B takes 128 days. The ratio of the radius of orbit taken by A to that by B is
A. 1 : 64
B. 1 : 32
C. 1 : 16
D. 1 : 8
8. A body is in simple harmonic motion of amplitude 0.50 m and period 4π seconds.
What is the speed of the body when the displacement of the body is 0.30 m?
A.
B.
C.
D.
0.10 ms-1
0.15 ms-1
0.20 ms-1
0.40 ms-1
9. The objective lens of an astronomical telescope has a diameter 30 mm and focal
length 0.5 m. The eyepiece has a focal length of 0.1 m and the instrument is in
normal adjustment. The diameter of the eye-ring is
A.
B.
C.
D.
7.5 mm
6 mm
4 mm
2 mm
4
10. A diffraction grating, used at normal incidence, gives a green line of wavelength
5.4 x 10-7 m in a certain order superimposed on the violet line of wavelength
4.05 x 10-7 m of the next order. If the angle of diffraction is 30o, the number of
lines per meter in the grating is
A.
B.
C.
D.
11.
1.8 x 105
3.09 x 105
4.26 x 105
1.35 x 106
Stationary waves are set up on a length of rope fixed at both ends. Which one of
the following statements is correct ?
A.
B.
C.
D.
Between adjacent nodes, particles of the rope vibrate in phase with
each other.
The mid point of the rope is always stationary.
Nodes need not necessarily be present at each end of the rope.
Particles of the rope at adjacent antinodes always move in the same
direction.
12.
Coherent monochromatic light of wavelength  emerges from the slits X and Y
to form dark fringes at P, Q, R and S in a double slit apparatus. Which one of the
following statements is correct ?
A.
B.
C.
D.
When the distance D is increased, the separation of the fringes
decreases.
When the distance between X and Y is increased, the separation of the
fringes decreases.
When the width of the slit T is decreased, the separation of the fringes
decreases.
1
There is a dark fringe at P because (YP – XP) is 2 .
2
5
13.
In a progressive sound wave, the displacement y of air molecules from their
mean position varies with the distance x from O as shown above. The
displacement towards the right is taken as positive. Which of the following
statements is / are correct ?
(1)
(2)
(3)
Compression is at Q.
Particle at P is moving to the right.
Particle at R is moving to the right.
A.
B.
C.
D.
(1) only
(3) only
(1) and (2) only
(2) and (3) only
14.
A capacitor of capacitance 10 F is fully charged through a resistor R to a p.d.
of 20 V using the circuit shown. Which one of the following statements is
INCORRECT ?
A.
B.
C.
D.
The p.d. across the capacitor is 20 V.
The p.d. across the resistor is 0 V.
The energy stored by the capacitor is 2 mJ.
The total energy taken from the battery during the charging process
is 2 mJ.
6
15.
P
30
1.2A
Q
S
R
A square coil PQRS, of 20 turns and length 0.15 m, is placed in a uniform
magnetic field of 0.4 T. The magnetic field is parallel to the plane of the
coil. The side PQ makes 30 with the magnetic field. The current in the
coil is 1.2 A. Calculate the magnetic force acting on PQ and QR of the coil.
A.
B.
C.
D.
Force on PQ
0.72 N
0.72 N
1.25 N
1.25 N
Force on QR
0.72 N
1.25 N
0.72 N
1.25 N
16.
4
p.d. / V
2
10 
10 
resistor
lamp
0
0.2
Current / A
0.4
3.0 V
The graph above shows the relationship between potential difference and current
for a particular filament lamp and a fixed 10  resistor. What is the current in
the circuit shown above?
A.
B.
C.
D.
0.10 A
0.20 A
0.30 A
0.35 A
7
17.
C
R
A
S
After the switch S is closed, the variable resistor R is reduced at a rate that the
charging current remains constant at 20 A for a time of 30 s. During this time,
the p.d. across the capacitor rises from 0 V to 12 V. What is the capacitance of
the capacitor?
A.
B.
C.
D.
8 F
20 F
50 F
200 F
18.
X
Z
uniform
magnetic
field
Y
The diagram shows a square coil with its plane parallel to a uniform magnetic
field. Which one of the following would induce an e.m.f. in the coil?
A.
B.
C.
D.
movement of the coil to the left
movement of the coil downwards
rotation of the coil about an axis through XY
rotation of the coil about an axis perpendicular to the plane of the
coil through Z
19. The second overtones of an open pipe X and a closed pipe Y have the same
frequency at a given temperature. The ratio of length of X to that of Y is
A. 3 : 5
B. 5 : 3
8
C. 6 : 5
D. 5 : 6
20. A battery, a resistor and a parallel plate capacitor are connected in series. If the
plates of the capacitor shown in the diagram are brought closer together. Which
of the following quantities will increase in magnitude ?
(1) The charges on both plates.
(2) The field between the plates.
(3) The potential differences across the plates.
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
21. The rotating coil of a motor has a resistance of 1 . When it is powered by a
supply of e.m.f. 24 V and negligible internal resistance, the current through the
coil is 4 A. What is the maximum useful output power delivered by the motor ?
A. 16 W
B. 32 W
C. 64 W
D. 80 W
22.
A sound source approaches an observer with a uniform acceleration towards
the observer. Which of the following statements is/are true ?
(1) The pitch heard by the observer is higher than that of the source.
(2) The pitch heard is increasing gradually,
(3) The initial pitch heard depends on the initial distance between the
source and the observer.
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
23.
A radio produce a sound intensity level of 50 dB at a point 2 m away from it. If
the power output of the radio is halved, what is the sound intensity level at a
point 4 m from the radio ? ( You may regard the radio as a point source )
9
A. 12.5 dB
B. 41.0 dB
C. 49.4 dB
D. 56.0 dB
24. 2 Hz beats are obtained when a flute and a 512 Hz tuning fork are sounded.
When the fork is doubled, the beat frequency becomes 4 Hz. What note(s) could
the flute have been playing ?
A. 510 Hz
B. 514 Hz
C. 508 Hz or 516 Hz
D. 510 Hz or 514 Hz
25. The work function of a piece of metal is  and the maximum kinetic energy of
the photoelectrons is emitted when a light shines on it. Which of the following
can increase the maximum kinetic energy of the emitted photoelectrons ?
(1) Increase the intensity of light
(2) Increase the frequency of light
(3) Replace the metal with a lower work function.
A. (1) only
B. (3) only
C. (1) and (2) only
D. (2) and (3) only
26. A mass M on a spring oscillates along a vertical line with the same period T as
an object O in uniform circular motion in a vertical plane. When M is at its
highest point, O is at its lowest point.
What is the least time interval between successive instants when the acceleration
of M is exactly in the opposite direction to the acceleration of O?
A.
B.
C.
D.
T
4
T
2
3T
4
T
10
27.
A L-shaped block ABC of weight 30 N rests on a horizontal ground. The
centre of mass of the block is at G. A horizontal force P is applied at point
A. When P reaches 20 N, the block overturns.
12 cm
P
A
G
15 cm
B
C
30 N
If the force P is applied in the opposite direction, what is its least value in
order to overturn the block?
A.
B.
C.
D.
4N
16 N
24 N
32 N
28. A satellite is in orbit at a height h above the surface of a planet of mass M and
radius R. What is the velocity of the satellite?
A.
B.
C.
D.
GM ( R  h)
R
GM ( R  h)
R
GM
( R  h)
GM
( R  h)
29.
Medium 1
Medium 2
11
The above wavefront diagram shows some waves passing through two
different media. Which of the following is /are possible conclusion(s) ?
Nature of wave
Medium 1
Medium 2
(1)
light waves
air
glass
(2)
sound waves
water
air
(3)
water waves
shallow water
deep water
A.
B.
C.
D.
(1) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
30.
y
S1
RS

Q
P
t
0
S2
(i)
(ii)
In a ripple tank, S1 and S2 are two coherent sources vibrating in the same
phase. Figure (i) shows the wave pattern at time t=0. The solid lines
represent the crests of the water waves.
Figure (ii) shows the
displacement-time graph of water particle at P.
What are the
PQ
displacement-time graphs for particle at R and S where PR 
and
4
PQ
PS 
?
2
12
y-t graph at R
A.
y-t graph at S
y
y
t
0
B.
t
t
t
0
t
y
y
0
0
y
y
0
D.
t
y
y
0
C.
0
t
0
t
31. Sound waves are emitted from a stationary source. When an observer is
moving towards the source, which of the following quantities increases?
(1)
(2)
(3)
The frequency of the sound waves detected by the observer.
The wavelength of the sound waves.
The speed of the sound waves.
A.
B.
C.
D.
(1) only
(2) only
(1) and (3) only
(2) and (3) only
32.
4 k
15 V
1 k
220 F
10 V
In steady state, which of the following statements is / are correct?
13
(1) The current passing through the 4 k resistor is 1 mA.
(2) The potential difference across the capacitor is 11 V.
(3) The charges stored in the capacitor 20 C.
A.
B.
C.
D.
(1) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
33. A capacitor of capacitance 15 F is fully charged and the potential difference
across its plates is 8.0 V. It is then connected into the circuit as shown.
The switch S is closed at time t = 0. Which one of the following statements is
correct?
A.
B.
C.
D.
The time constant of the circuit is 6.0 ms.
The initial charge on the capacitor is 12 C.
After a time equal to twice the time constant, the charge remaining
on the capacitor is Q0e2, where Q0 is the charge at time t = 0.
After a time equal to the time constant, the potential difference
across the capacitor is 2.9 V.
34.
Y
A
X
B
P
Q
Two long solenoids, X and Y, placed coaxially as shown above. The data about
the solenoids are listed below:
radius
turn density
current
Solenoid X
5 cm
1200 m-1
1.0 A
(clockwise viewed
from B)
Solenoid Y
3 cm
2400 m-1
0.5 A
(anticlockwise
viewed from B)
14
Point P is on the common axis and Point Q is 4 cm from the axis.
The
permeability of the air is 4  10 Hm . Which of the following statements is /
are correct ?
-7
-1
(1) The magnetic field at P is zero.
(2) The magnetic field at Q is 1.5 mT.
(3) The magnetic field at Q points to the left.
A.
B.
C.
D.
(1) only.
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
35. A circular coil of 200 turns and radius 4 cm is fixed in a uniform magnetic field
which is perpendicular to the plane of the coil. The coil’s total resistance is 10
. The flux density of the field is increased at a uniform rate of 0.5 T s -1 in the
first 5 s. It is then kept constant for another 5 s.








































uniform
magnetic
field
Which of the following graphs correctly show the variation of the current I
induced in the coil from time t = 0 to t = 10 s.
A.
B.
I/mA
I/mA
5
5
0
5
10
0
t/s
C.
5
10
t/s
5
10
t/s
D.
I/mA
I/mA
50
0
50
5
10
t/s
0
15
36. An a.c. circuit has a total impedance of 13  and a total reactance of 5 .
What is the average power dissipated in the circuit when the r.m.s. current
passing through it is 2 A ?
A.
B.
C.
D.
4W
20 W
48 W
52 W
37.
C
R

V
A capacitor C and a resistor R is connected in series with an a.c. supply V. VC
and VR denote the phasors of the p.d. across the capacitor and that across the
resistor respectively. Which of the following phasor diagrams is correct?
A.
B.
VR
VC
VC
C.
VR
D.
VR
VC
VC
38.
VR
p / kPa
B
200
A
C
100
0
V / m3
0.2
0.4
16
A fixed mass of an ideal gas undergoes the process ABC as shown in the
pressure-volume diagram.
process?
What is the work done on the gas during the
1 x 104 J
3 x 104 J
–1 x 104 J
–3 x 104 J
A.
B.
C.
D.
39.
P/105 Pa
8
6
4
2
V/m3
0
2
4
6
8
10
12
14
The pressure P of a fixed mass of ideal gas changes with its volume V as
shown above. Which of the following graphs shows the corresponding
pressure-temperature (P-T) relationship?
A.
B.
P/105 Pa
P/105 Pa
8
8
6
4
2
6
4
2
T
0
C.
T
0
D.
P/105 Pa
P/105 Pa
8
8
6
4
2
0
T
6
4
2
0
40. Which of the following equations is / are based on the principle of conservation
of energy ?
T
17
1
mv2
2
(2) U = Q + W
1
(3) p + v2 + gh = constant
2
(1) hf = W +
A.
B.
C.
D.
(1) and (2) only
(1) and (3) only
(2) and (3) only
(1), (2) and (3)
41. The apparatus shown in the diagram is designed to accelerate alpha particles.
An alpha particle travelling at a speed of 2.60 × 106 ms−1 passes through a hole
in plate A. The mass of an alpha particle is 6.64 × 10−27 kg and its charge is 3.2
× 10−19C. The e.m.f. of the power supply is 2.5 x 104 V and has negligible
internal resistance. Calculate the kinetic energy of the alpha particle when it
reaches plate B.
A.
B.
C.
D.
8.00 × 10-15 J
1.52 × 10-14 J
2.24 × 10-14 J
3.04 × 10−14 J.
42. In Rutherford experiment, one alpha particle, of kinetic energy 7.7 MeV, is
bombarding towards a distant gold nucleus. The alpha particle is deflected
as shown. Calculate the kinetic energy of the alpha particle at P where is
6.5 x 10-14 m from the gold nucleus.
(Given: charge of an electron = 1.6 x10-19 C;
permittivity of vacuum = 8.85 x 10-12 F m-1;
atomic number of gold = 79;
atomic number of alpha particle = 2.)
18
P
Alpha
particle
Gold nucleus
A.
B.
C.
D.
3.5 MeV
4.2 MeV
7.3 MeV
11.2 MeV
43. If monochromatic light of wavelength 420 nm is incident on a metal plate,
electron will be emitted. The work function of the metal is 3.4 x 10-19 J.
Which of the followin g are the possible of the kinetic energy of the emitting
electrons.
(Given: Planck constant = 6.6 x10-34 Js;
mass of an electron = 1.6 x 10-19 C)
(1) 0.41 eV
(2) 0.82 eV
(3) 1.64 eV
A.
B.
C.
D.
(1) only
(1) and (2) only
(2) and (3) only
(1), (2) and (3)
44.
n=4
n=3
-1.6 eV
-2.7 eV
n=2
-5.5 eV
n=1
-10.4 eV
The figure shows the possible energy levels of a mercury atom. A free electron
with kinetic energy 8.4 eV collides with a mercury atom, which is in its ground
state. The change in kinetic energy of the mercury atom in the collision may be
neglected. What is/are the possible value(s) for the kinetic energy of the
electron after collision ?
19
(1)
(2)
(3)
0.7 eV
2.9 eV
3.5 eV
A.
B.
C.
D.
(1) only
(2) only
(1) and (3) only
(2) and (3) only
45.
ln A
Y
X
0
T
2T
t
The activity A of a radioactive sources X and Y are measured at different time.
Graphs of ln A against time t for X and Y are shown above. Which of the
following statements is/are correct ?
(1) The initial activity of source X and Y are equal.
(2) The half life of Y is twice that of X.
(3) At t = 0, the number of active nuclides of Y is twice that of X.
A.
B.
C.
D.
(1) and (2) only
(1) and (3) only
(2) and (3) only
(1), (2) and (3)
END OF SECTION A
Section B
Answer any THREE questions for this Section. Write your answers in the ANSWER
BOOK provided. Where necessary, take the acceleration due to gravity to be 10 m s-2
and take the speed of light in air to be 3 x 108 m s-1.
20
1.
a.
b. i.
ii.
State Newton’s law of universal gravitation.
( 1 mark )
What is meant by the term ‘weightlessness’ ?
Astronauts inside a space shuttle orbiting around the
Earth usually appear to be weightless. Give a brief
explanation of this with the help of suitable force
diagrams.
iii. State another situation in which one can experience
( 5 marks )
weightlessness.
c.
Suppose that a satellite with mass m is orbiting around
the Earth at a distance r from its centre. The mass and
the radius of the Earth are respectively M and R
i.
Explain why the orbit of the satellite must lie at the
equator plane of the Earth.
ii. Deduce mathematically the expressions for the potential
energy, the kinetic energy and the total energy of the
satellite.
iii.By using the result in (c)(ii), sketch, on the same graph, the
variation of the potential energy, the kinetic energy and
the total energy of the satellite with its distance from
the Earth starting from r = R to r =  .
iv. What would happen to the motion of the satellite when ( 10 marks )
it is subject to air resistance ? Explain briefly.
2.
a.
What is the principle of superposition? Use this
principle to explain the formation of antinodes and
nodes in the stationary wave.
What are beats and describe briefly how they are
produced? Briefly describe how the measurement of
beats would be used to detect the speed of cars in a
police radar speed check system.
With the aid of a diagram, explain qualitatively why
different colours are observed on a soap bubble under
sunlight.
Explain why Polaroid sunglass can effectively reduce
the glare of the sun reflecting from the sea.
b.
c.
d.
3.
a.
i.
ii.
b.
(5 marks)
(5 marks)
(3 marks)
(3 marks)
Describe and explain briefly the methods adopted in
a steady magnetic field using a Hall probe.
an alternating magnetic field using a search coil.
Compare the different physical mechanisms in these ( 11 marks )
two methods and derive any necessary mathematical
expressions.
Comment briefly on the main factors that might affect
the accuracy of the measurements.
( 5 marks )
21
4.
a.
A
B
R
i.
ii.
b.
By considering a unit charge moving round the above
circuit, distinguish between the electromotive force
(e.m.f.) of the battery and the potential difference (p.d.)
across its terminals A and B. Explain why, in general,
the p.d. across the terminals of the battery is lower than
its e.m.f.
The resistor R is about 10 k. Draw a circuit diagram
to show how a moving-coil milliammeter and a
voltmeter should be connected in the circuit in order to
measure the resistance R. Explain whether the value R
calculated from the readings of the milliammeter and
voltmeter would be greater or smaller than its actual
( 6 marks )
value.
Consider a fixed mass of an ideal gas contained in a
cubical box. Show that, from first principles, the
pressure p of the gas is proportional to the mean square
speed c 2 of the gas molecules. State the major
( 10 marks )
assumption(s) you have made.
*** END OF PAPER ***
22