E08. OSCILLATIONS,WAVESANDWAVEPHENOMENA TestCandidates
1.
Water waves at the surface of a pond pass a floating log of length L. The log is at rest relative to
the bank. The diagram shows wave crests at one instant.
L
The number of crests passing the log per unit time is N. The speed of the water waves relative to
the log at rest is
A.
L
(N – 1).
7
B.
L
(N – 1).
6
C.
L
(N).
7
D.
L
(N).
6
(1)
2.
Two identical triangular pulses of amplitude X travel toward each other along a string. At the
instant shown on the diagram below, point M is midway between the two pulses.
X
X
M
1
The amplitude of the disturbance in the string as the pulses move through M is
A.
2X.
B.
X.
C.
D.
X
.
2
0.
(1)
3.
A person is walking along one side of a building and a car is driving along another side of the
building.
The person can hear the car approach but cannot see it. This is explained by the fact that sound
waves
A.
travel more slowly than light waves.
B.
are diffracted more at the corner of the building than light waves.
C.
are refracted more at the corner of the building than light waves.
D.
are longitudinal waves.
(1)
2
4.
A pulse is sent down a string fixed at one end.
Which one of the following diagrams best represents the reflected pulse?
A.
B.
C.
D.
(1)
5.
A sound emitting source moves along a straight line with speed v relative to an observer at rest.
Observer
v
The speed of sound relative to the medium is c. The observer measures the speed of sound
emitted by the source as
A.
c.
B.
c + v.
C.
c – v.
D.
v – c.
(1)
3
6.
The diagram below shows ocean waves incident on a stone barrier protecting boats anchored
behind it.
Waves
Boats
Barrier
The boats could still be at risk of damage by waves mainly as a result of
A.
refraction.
B.
standing waves.
C.
diffraction.
D.
reflection.
(1)
7.
A plane wave approaches and passes through the boundary between two media. The speed of
the wave in medium 1 is greater than that in medium 2. Which one of the following diagrams
correctly shows the wavefronts?
A.
B.
Medium 1
Medium 1
Medium 2
Medium 2
C.
D.
Medium 1
Medium 2
Medium 1
Medium 2
(1)
4
8.
1
l apart on a stationary wave of wavelength λ.
2
The variation with time t of the displacement dx of X is shown below.
Two particles X and Y are situated a distance
dX
0
0
t
Which one of the following correctly shows the variation with time t of the displacement dY of
particle Y?
A.
0
0
C.
B.
dY
0
0
0
0
t
D.
dY
t
dY
t
dY
0
0
t
(1)
5
9.
The speed of a wave is defined as
A.
the speed at which the particles of the wave vibrate.
B.
the speed of the medium through which the wave passes.
C.
the speed of transfer of the energy of the wave.
D.
the speed at which the vibrations of the wave are produced.
(1)
10.
Which diagram best shows diffraction of plane wavefronts at a single slit?
A.
B.
C.
D.
(1)
6
11.
A source of sound moves directly towards a stationary observer. The frequency of the sound
detected by the observer is different from the source frequency because
A.
the loudness of the sound increases as the source moves towards the observer.
B.
the apparent wavelength of the sound is longer.
C.
the speed of sound relative to the observer is increased.
D.
the apparent wavelength of the sound is shorter.
(1)
12.
The diagram shows the variation with distance x along a wave with its displacement d.
The wave is travelling in the direction shown.
d
direction of travel
x
7
The period of the wave is T. Which one of the following diagrams shows the displacement of
T
the wave at
later?
4
A.
B.
d
d
x
C.
x
D.
d
d
x
x
(1)
13.
When a wave crosses the boundary between two media, which one of the following properties
of the wave does not change?
A.
Amplitude
B.
Wavelength
C.
Frequency
D.
Speed
(1)
8
14.
A pipe, open at both ends, has a length L. The speed of sound in the air in the pipe is v. The
frequency of vibration of the fundamental (first harmonic) standing wave that can be set up in
the pipe is
A.
v
.
2L
B.
L
.
2v
C.
4v
.
L
D.
L
.
4v
(1)
15.
Jeremy is walking alongside a building and is approaching a road junction. A fire engine is
sounding its siren and approaching the road along which Jeremy is walking.
Jeremy
Building
Fire engine
Jeremy cannot see the fire engine but he can hear the siren. This is due mainly to
A.
reflection.
B.
refraction.
C.
the Doppler effect.
D.
diffraction.
(1)
9
16.
Two lamps producing light of the same colour are placed close to one another. A two source
interference pattern is not observed because
A.
the lamps do not emit light of a single frequency.
B.
the phase difference between the light from the lamps is continually changing.
C.
the intensity of the light emitted by the lamps is not the same.
D.
the two lamps are not exact point sources.
(1)
10
17.
On which one of the following graphs is the wavelength λ and the amplitude a of a wave
correctly represented?
l
A.
Displacement
0
0
Distance along
wave
a
l
B.
Displacement
0
0
Distance along
wave
a
l
C.
Displacement
0
0
Distance along
wave
a
l
D.
Displacement
0
0
a
Distance along
wave
(1)
11
18.
Standing waves in an open pipe come about as a result of
A.
reflection and superposition.
B.
reflection and diffraction.
C.
superposition and diffraction.
D.
reflection and refraction.
(1)
19.
The diagram below shows two wave pulses moving towards one another.
Which one of the following diagrams shows the resultant pulse when the two pulses are
superposed?
A.
B.
C.
D.
(1)
12
20.
A source of sound emits waves of wavelength λ, period T and speed v when at rest. The source
moves away from a stationary observer at speed V, relative to the observer. The wavelength of
the sound waves, as measured by the observer is
A.
λ + vT.
B.
λ – vT.
C.
λ +VT.
D.
λ – VT.
(1)
21.
What change, if any, occurs in the wavelength and frequency of a light wave as it crosses a
boundary from air into glass?
Wavelength
Frequency
A.
Decreases
Decreases
B.
Decreases
Unchanged
C.
Increases
Increases
D.
Increases
Unchanged
(1)
13
22.
The variation with time t of the separate displacements d of a point in a medium due to two
waves is shown below.
d
+2a
+a
0
t
–a
–2a
d
+a
0
t
–a
The waves are superposed. Which of the following diagrams shows the variation with time t of
the resultant displacement d of the point in the medium?
A.
d
0
C.
B. d
+a
t
+a
0
–a
–a
d
+3a
D. d
+3a
+2a
+2a
+a
+a
0
t
0
–a
–a
–2a
–2a
–3a
–3a
t
t
(1)
14
23.
Which of the following diagrams best illustrates the diffraction of waves by an obstacle?
A.
B.
C.
D.
(1)
15
24.
A source S produces sound waves of frequency f and is moving along a straight line as shown
below.
I
IV
S
II
III
Which observer I, II, III or IV could hear a sound of frequency f when the source is in the
position shown?
A.
I
B.
II
C.
III
D.
IV
(1)
25.
In order that the interference between the waves emitted by two light sources can be observed, it
is essential that the sources must emit waves that
A.
have the same amplitude.
B.
are in phase.
C.
have the same colour.
D.
have a constant phase difference between them.
(1)
16
26.
The wavelength of a progressive transverse wave is defined as
A.
the distance between a crest and its neighbouring trough.
B.
the distance between any two crests of the wave.
C.
the distance moved by a wavefront during one oscillation of the source.
D.
the distance moved by a particle in the wave during one oscillation of the source.
(1)
27.
The two graphs show the variation with time of the individual displacements of two waves as
they pass through the same point.
displacement
A1
x1
0
0
T
time
–A1
displacement
A2
0
–x20
–A2
time
T
17
The displacement of the resultant wave at the point at time T is equal to
A.
x1 + x2 .
B.
x1 – x2 .
C.
A1 + A2.
D.
A1 – A2.
(1)
28.
Graph P shows how the displacement at one point in a wave varies with time.
Graph Q shows how the displacement in the same wave varies with distance along the wave at
one particular time.
Graph P
displacement
0
0
t1
t2
time
Graph Q
displacement
0
0
x1
x2
x3
distance
18
Which one of the following expressions gives the speed of the wave?
A.
x1
t1
B.
x2
t2
C.
(x 2 - x1 )
(t 2 - t1 )
D.
(x3 - x1 )
(t 2 - t1 )
(1)
29.
A string is stretched between two fixed points. The string is plucked at its centre and is seen to
vibrate with frequency f as shown below.
Which one of the following expressions gives the frequencies of other possible modes of
vibration that have an antinode at the centre? The number n in each expression is an integer.
A.
nf
B.
(2n – 1)f
C.
(n – 1)f
D.
(n + 1)f
(1)
19
30.
Which one of the following diagrams best represents wavefronts produced by a source of sound
of constant frequency as it moves at constant speed towards a stationary observer at O?
A.
B.
O
C.
O
D.
O
O
(1)
31.
The waves from two light sources meet at a point. Which condition is essential for interference
to be observed?
A.
Constant phase difference between the waves
B.
Equal amplitude of the waves
C.
Equal frequency of the waves
D.
Equal intensities of the waves
(1)
20
32.
Light from a double slit arrangement produces bright and dark fringes on a screen in the region
near point P, as indicated below.
P
coherent
light
screen
double slit
not to scale
The light from the two slits has equal amplitudes on reaching point P.
Which one of the following gives the change, if any, in the appearance of the bright and the
dark fringes when the amplitude of the light wave from one slit is reduced?
Bright fringes
Dark fringes
A.
Remains the same
Remains the same
B.
Becomes less bright
Remains the same
C.
Becomes less bright
Becomes more bright
D.
Remains the same
Becomes more bright
(1)
33.
The graph below shows the variation of air pressure with distance along a wave at one given
time. The arrow indicates the direction of travel of the wave.
air pressure
+
normal air pressure
P
distance along wave
–
21
The air pressure at point P is
A.
increasing.
B.
decreasing.
C.
constant.
D.
zero.
(1)
34.
Sound waves move faster in warm air than in cold air. The diagram below shows plane waves in
cold air moving towards a boundary with warm air.
I
warm air
II
III
boundary
cold air
IV
Which of the arrows shows the possible direction of waves after reaching the boundary?
A.
I
B.
II
C.
III
D.
IV
(1)
22
35.
The speed of sound in still air is c. A source of sound moves away from an observer at speed v.
What will be the speed of sound as measured by the observer?
A.
c
B.
c+v
C.
c–v
D.
v–c
(1)
36.
For a standing wave, all the particles between two successive nodes have the same
A.
amplitude only.
B.
frequency only.
C.
amplitude and frequency.
D.
frequency and energy.
(1)
23
37.
The diagram below shows two pulses on a string travelling toward each other.
Which of the following diagrams best shows the shape of the string after the pulses have passed
through each other?
A.
B.
C.
D.
(1)
38.
Two identical sources in a ripple tank generate waves of wavelength λ. The interfering waves
produce the wave pattern shown below.
II
III
I
IV
24
Along which of the labelled lines is the path difference between the waves from the sources
equal to 1.5 λ?
A.
I
B.
II
C.
III
D.
IV
(1)
39.
Diagram 1 below shows the displacement of part of a medium through which a wave is
travelling at time t = 0. Diagram 2 shows the displacement at a later time t = 4.0 s in which the
wave has moved forward 10 cm. In this time, the point P on the wave has moved from a crest
through zero displacement to a trough.
Diagram 1
Diagram 2
P
P
The wavelength of the wave is
A.
5.0 cm.
B.
10 cm.
C.
20 cm.
D.
40 cm.
(1)
25
40.
The diagram below shows a pulse travelling along a rope from X to Y. The end Y of the rope is
tied to a fixed support.
X
Y
When the pulse reaches end Y it will
A.
disappear.
B.
cause the end of the rope at Y to oscillate up and down.
C.
be reflected and be inverted.
D.
be reflected and not be inverted.
(1)
41.
Which one of the following is correct for transfer of energy along a standing wave and for
amplitude of vibration of the standing wave?
Transfer of energy along
a standing wave
Amplitude of vibration of
the standing wave
A.
None
Constant amplitude
B.
None
Variable amplitude
C.
Energy is transferred
Constant amplitude
D.
Energy is transferred
Variable amplitude
(1)
26
42.
Two pipes P and Q are of the same length. Pipe P is closed at one end and pipe Q is open at
both ends. The fundamental frequency (first harmonic) of the closed pipe P is 220 Hz.
The best estimate for the fundamental frequency of the open pipe Q is
A.
880 Hz.
B.
440 Hz.
C.
110 Hz.
D.
55 Hz.
(1)
43.
In order that the light from two sources produces an observable interference pattern, it is
necessary that
A.
the sources must be point sources.
B.
the light emitted by the sources must be monochromatic.
C.
the light from each source must be of the same intensity.
D.
the light from the sources must be coherent.
(1)
27
44.
A source produces water waves of frequency 10 Hz. The graph shows the variation with
horizontal position of the vertical displacement of the surface of water at one instant in time.
vertical displacement / cm
0.4
00
1.0
2.0
3.0
4.0
horizontal position / cm
–0.4
The speed of the water waves is
A.
0.20 cm s−1.
B.
4.0 cm s−1.
C.
10 cm s−1.
D.
20 cm s−1.
(1)
45.
A wave travels from one medium to another. Which of the following is true about its frequency
and wavelength?
Frequency
Wavelength
A.
No change
No change
B.
Change
No change
C.
No change
Change
D.
Change
Change
(1)
28
46.
A bat approaches an insect of wing span length d. The bat emits a sound wave. The bat detects
the insect if the sound is reflected from the insect.
d
refected waves
incident waves
The insect will not be located if
A.
the insect’s speed is less than the speed of the sound wave.
B.
the insect’s wing beat frequency is greater than the frequency of the sound wave.
C.
the length d is much greater than the wavelength of the sound wave.
D.
the length d is much smaller than the wavelength of the sound wave.
(1)
47.
Monochromatic light crosses the boundary between two media. Which of the following
quantities is always the same for the light in both media?
A.
Amplitude
B.
Frequency
C.
Speed
D.
Wavelength
(1)
29
48.
A point source is moving at a constant speed in a straight-line towards the right and emits sound
waves of constant frequency. The speed of the source is less than the speed of sound. Which of
the diagrams correctly shows the wavefronts emitted by the source?
A.
B.
C.
D.
(1)
30
49.
The diagram below shows the arrangement for a Young’s double slit experiment.
single slit
double slit
S1
monochromatic light source
S
S2
The function of the single slit is
A.
to direct the light towards S1 and S2.
B.
to ensure equal intensities of light at S1 and S2.
C.
to produce coherent light at S1 and S2.
D.
to reduce the intensity of light at S1 and S2.
(1)
31
50.
The diagram below shows a transverse wave on a string. The wave is moving from right to left.
X
Y
direction of wave
upwards
left
right
downwards
In the position shown, point X has zero displacement and point Y is at a position of maximum
displacement. Which one of the following gives the subsequent direction of motion of point X
and of point Y?
Point X
Point Y
A.
left
left
B.
upwards
upwards
C.
downwards
left
D.
downwards
upwards
(1)
32
51.
Light is incident on an air-glass boundary as shown below.
Q
air
P
R
glass
S
Which one of the following is a correct statement of Snell’s law?
A.
sin P = constant ´ sin R
B.
sin P = constant ´ sin S
C.
sin Q = constant ´ sin R
D.
sin Q = constant ´ sin S
(1)
52.
Which one of the following correctly describes the change, if any, in the speed, wavelength and
frequency of a light wave as it passes from air into glass?
Speed
Wavelength
Frequency
A.
decreases
decreases
unchanged
B.
decreases
unchanged
decreases
C.
unchanged
increases
decreases
D.
increases
increases
unchanged
(1)
33
53.
A tube is filled with water and a vibrating tuning fork is held above its open end.
tuning fork
x
y
water
tap
The tap at the base of the tube is opened. As the water runs out, the sound is loudest when the
water level is a distance x below the top of the tube. A second loud sound is heard when the
water level is a distance y below the top. Which one of the following is a correct expression for
the wavelength l of the sound produced by the tuning fork?
A.
l=y
B.
l = 2x
C.
l=y−x
D.
l = 2(y − x)
(1)
34
54.
A source S, moving at constant speed, emits a sound of constant frequency. The source passes
by a stationary observer O, as shown below.
S
O
Which one of the following shows the variation with time t of the frequency f observed at O as
the source S approaches and passes by the observer.
A.
0
C.
B.
f
0
0
0
t
D.
f
0
t
f
0
t
0
t
f
0
(1)
35
55.
Water waves of wavelength 2.0 m are produced by two sources S1 and S2. The sources vibrate
in phase.
S1
S2
1m
3m
P
Point P is 1 m from S1 and 3 m from S2. S1 alone and S2 alone each produce a wave of
amplitude a at P. Which one of the following is the amplitude of the resultant wave at point P
when S1 and S2 are both emitting waves?
A.
2a
B.
a
C.
1
a
2
D.
Zero
(1)
36
56.
A string is held horizontally with one end attached to a fixed support. Two pulses are created at
the free end of the string. The pulses are moving towards the fixed support as shown in the
diagram below.
fixed support
string
Which one of the following diagrams is a possible subsequent picture of the string?
A.
B.
C.
D.
(1)
57.
A water surface wave (ripple) is travelling to the right on the surface of a lake. The wave has
period T. The diagram below shows the surface of the lake at a particular instant of time. A
piece of cork is floating in the water in the position shown.
Which is the correct position of the cork a time
T
later?
4
cork
A.
C.
B.
D.
(1)
37
58.
A source of sound is placed near the open end of a cylindrical tube that lies on a horizontal table.
The tube has some powder sprinkled along its length. The powder collects in piles along the
length of the tube as shown below.
source of sound
d
The distance between two consecutive piles of powder is d and the speed of sound in the tube is
v. The frequency of the source is
A.
v
.
2d
B.
v
.
d
C.
dv.
D.
2dv.
(1)
38
59.
A stationary source emits sound of frequency f0. An observer is moving towards the source at
constant speed along the path indicated by the dotted line. The observer passes very close to the
source at time T.
stationary source
observer
Which one of the following graphs best shows the variation with time t of the frequency f heard
by the observer?
A.
f
B.
f0
f0
T
C.
f
t
D.
f
f0
T
t
T
t
f
f0
T
t
(1)
39
60.
A wave is travelling through a medium. The diagram shows the variation with time t of the
displacement d of a particle of the medium from t = 0 to t = 25 ms.
1.5
1
d/cm
0.5
00
5
10
15
20
25
t/ms
–0.5
–1
–1.5
Which of the following correctly gives the frequency and the amplitude of the wave?
frequency / Hz
amplitude / cm
A.
2.0 ´ 10–2
2.0
B.
2.0 ´ 10–2
1.0
C.
50
2.0
D.
50
1.0
(1)
40
61.
Waves of frequency f travel with speed c in air and enter a medium M of refractive index 1.5.
Which of the following correctly gives the frequency and speed of the waves in the medium M?
frequency
speed
A.
f
c
1.5
B.
f
1.5c
C.
1.5f
c
D.
f
1.5
c
(1)
41
62.
Plane wavefronts are incident on a barrier as shown below.
barrier
Which of the following best shows the shape of the wavefronts on the other side of the barrier?
A.
B.
C.
D.
(1)
42
63.
A police car, sounding its siren, is travelling at constant speed towards a stationary observer.
The sound emitted by the siren is of constant frequency. The frequency of the sound as heard by
the observer is higher than that heard by the driver of the police car. The reason for this is that
A.
the wavefronts received by the observer are closer together than the wavefronts received
by the driver.
B.
the speed of the wavefronts is greater as measured by the observer than by the driver.
C.
the speed of the wavefronts is less as measured by the observer than by the driver.
D.
the wavefronts received by the observer are further apart than the wavefronts received by
the driver.
(1)
64.
The light waves emitted by two coherent sources overlap and form an observable interference
pattern. The word coherent in this situation means that
A.
the sources are point sources.
B.
there is a constant phase difference between the light waves emitted by the sources.
C.
the sources emit light of the same frequency.
D.
the sources emit light of the same amplitude.
(1)
65.
Which of the following best describes the wave speed of a progressive wave travelling through
a medium?
A.
The maximum speed of the vibrating particles of the medium
B.
The average speed of the vibrating particles of the medium
C.
The speed of the medium through which the wave travels
D.
The speed of transfer of energy through the medium
(1)
43
66.
Which of the following diagrams best shows the path of a ray of monochromatic light through a
glass prism in air?
B.
A.
glass
air
glass
air
D.
C.
glass
air
glass
air
(1)
67.
Plane parallel wavefronts are incident on an obstacle. Which of the following diagrams best
shows the diffraction of the waves around the obstacle?
A.
B.
C.
D.
(1)
44
68.
A vibrating tuning fork is held above the top of a tube that is filled with water. The water
gradually runs out of the tube until a maximum loudness of sound is heard.
Which of the following best shows the standing wave pattern set up in the tube at this position?
A.
B.
C.
D.
(1)
69.
Which of the following is a correct description of the Doppler effect?
A.
Change in frequency of light due to motion of the source of light.
B.
Change in frequency of light due to relative motion between the source of light and the
observer.
C.
Change in observed frequency of light due to relative motion between the source of light
and the observer.
D.
Change in observed frequency of light due to change in velocity of the source of light.
(1)
45
70.
In a double-slit experiment using coherent light of wavelength l, the central bright fringe is
observed on a screen at point O, as shown below.
P
coherent light
O
wavelength l
double slit
screen
(not to scale)
At point P, the path difference between light arriving at P from the two slits is 4l.
Which of the following correctly describes the observed fringe pattern?
nature of fringe at P
number of dark fringes between O and P
A.
bright
3
B.
bright
4
C.
dark
3
D.
dark
4
(1)
71.
The phenomenon of diffraction is associated with
A.
sound waves only.
B.
light waves only.
C.
water waves only.
D.
all waves.
(1)
46
72.
The diagram below shows plane wavefronts of a wave that is approaching the boundary
between two media, X and Y. The speed of the wave is greater in medium X than in medium Y.
The wave crosses the boundary.
boundary
medium X
medium Y
Which of the following diagrams is correct?
A.
B.
medium X
medium Y
C.
medium X
medium Y
medium X
medium Y
D.
medium X
medium Y
(1)
47
73.
The graph below shows the variation with time t of the separate displacements d of a medium,
at a particular point in the medium due to two waves, P and Q.
d / mm
1.0
0.5
wave Q
0.0
t
0
–0.5
wave P
–1.0
The amplitude of the wave resulting from the interference of P and Q is
A.
0.0 mm.
B.
1.0 mm.
C.
1.4 mm.
D.
2.0 mm.
(1)
74.
One end of a long string is vibrated at a constant frequency f. A travelling wave of wavelength l
and speed v is set up on the string.
The frequency of vibration is doubled but the tension in the string is unchanged. Which of the
following shows the wavelength and speed of the new travelling wave?
Wavelength
A.
B.
λ
2
λ
2
Speed
v
2v
C.
2l
v
D.
2l
2v
(1)
48
75.
A string with both ends fixed is made to vibrate in the second harmonic mode as shown by the
dashed lines in the diagram below.
P
Q
The solid line shows a photograph of the string at a particular instant of time. Two points on the
string have been marked P and Q.
Which of the following correctly compares both the period of vibration of P and Q and the
average speed of P and Q?
Period
Average speed
A.
same
same
B.
same
different
C.
different
same
D.
different
different
(1)
76.
A transverse travelling wave has amplitude A0 and wavelength λ.
The distance between a crest and its neighbouring trough, measured in the direction of energy
transfer of the wave is equal to
A.
A0.
B.
2A0.
C.
D.
l
2
.
λ.
(1)
49
77.
A light wave travelling through a vacuum is incident on a block of glass. What change, if any,
occurs in the frequency and amplitude of the wave as it travels into the glass?
frequency
amplitude
A.
decreases
decreases
B.
decreases
constant
C.
constant
decreases
D.
constant
constant
(1)
78.
Which statement is true for standing (stationary) waves?
A.
All points in the wave vibrate in phase.
B.
There is no energy in a standing wave.
C.
The wavelength of the wave is the distance between adjacent nodes.
D.
Neighbouring points in the wave have different amplitudes of vibration.
(1)
79.
A stationary source of sound emits waves of wavelength λ, period T and speed V. The source
now moves with speed v in a straight line away from a stationary observer.
What are the wavelength and the speed of the wave as detected by the observer?
wavelength
speed
A.
λ
V+v
B.
λ – vT
V
C.
λ
V–v
D.
λ + vT
V
(1)
50
80.
Which two conditions are necessary for observable interference between two light beams?
A.
meet at a point
constant phase difference
B.
constant phase difference
similar amplitude
C.
same frequency
similar amplitude
D.
similar amplitude
meet at a point
(1)
81.
Light travelling from water to air is incident on a boundary.
Y
Z
X
air
water
W
Which of the following is a correct statement of Snell’s law for this situation?
A.
sin Z = constant × sin Y
B.
sin W = constant × sin Z
C.
sin X = constant × sin Z
D.
sin W = constant × sin Y
(1)
51
82.
A standing wave is established on a string between two fixed points.
T
A
B
U C
D
At the instant shown, point T is moving downwards. Which arrow gives the direction of
movement of point U at this instant?
A.
A
B.
B
C.
C
D.
D
(1)
52
83.
A pulse is travelling along a string attached to a wall.
pulse direction
Which of the following shows the shape of the string after reflection from the wall?
A.
B.
C.
D.
(1)
53
84.
The diagram below shows the displacement-position graph at a particular instant for a
longitudinal wave travelling along a spring.
displacement to right
+
0
displacement to left
–
C
0
B
D
position
A
A positive displacement on the graph indicates that the coils of the spring are displaced to the
right of their equilibrium position.
At which position along the spring is the displacement of two adjacent coils a maximum?
A.
A
B.
B
C.
C
D.
D
(1)
54
85.
The diagrams below show two standing wave patterns that are set up in a stretched string fixed
at both ends. The frequency of pattern 1 is f1 and that of pattern 2 is f2.
pattern 1
frequency f1
pattern 2
frequency f2
The ratio
A.
1
.
3
B.
2
.
3
C.
3.
D.
6.
f1
is
f2
(1)
86.
Sound of a constant frequency f0 is being emitted by a sound source. An observer O travels in
the direction shown at a speed of 0.1 v where v is the speed of sound.
observer
O
sound source
Which of the following gives the relationship between f0 and the frequency f of observed sound?
A.
f = 1.1f0
B.
f0 < f < 1.1f0
C.
f = 0.9f0
D.
f0 > f > 0.9f0
(1)
87.
The graph below shows the variation with time t of the displacement x of a particle undergoing
55
simple harmonic motion.
Which graph correctly shows the variation with time t of the acceleration a of the particle?
(1)
56
88.
A wooden block is at rest on a horizontal frictionless surface. A horizontal spring is attached
between the block and a rigid support.
The block is displaced to the right by an amount X and is then released. The period of
oscillations is T and the total energy of the system is E.
For an initial displacement of
X
which of the following shows the best estimate for the period
2
of oscillations and the total energy of the system?
Period
A.
T
B.
T
C.
D.
Total energy
E
2
E
4
E
2
E
4
T
2
T
2
(1)
89.
Which of the following correctly describes the change, if any, in the speed, wavelength and
frequency of a light wave as it passes from air into glass?
Speed
Wavelength
Frequency
A.
decreases
decreases
unchanged
B.
decreases
unchanged
decreases
C.
unchanged
increases
decreases
D.
increases
increases
unchanged
(1)
57
90.
Unpolarized light of intensity I0 is incident on a polarizer. The transmitted light is then incident
on a second polarizer. The axis of the second polarizer makes an angle of 60° to the axis of the
first polarizer.
The cosine of 60° is
A.
I0 .
B.
I0
.
2
C.
I0
.
4
D.
I0
.
8
1
. The intensity of the light transmitted through the second polarizer is
2
(1)
58