4 Waves
Exam-style questions
AQA Physics
1
a
Define the amplitude of a wave.
(1 mark)
b i
Other than electromagnetic radiation, give one example of a wave that is
transverse.
(1 mark)
ii
State one difference between a transverse wave and a longitudinal wave.
(1 mark)
c
Figure 1 shows two identical polarising filters, A and B, and an unpolarised
light source. The arrows indicate the plane in which the electric field of the
wave oscillates.
i If polarised light is reaching the observer, draw the direction of the
transmission axis on filter B in Figure 1.
Figure 1
ii
The polarising filter B is rotated clockwise through 360° about line XY
from the position shown in Figure 2. On the axes below, sketch how the
light intensity reaching the observer varies as this is done.
Figure 2
(2 marks)
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1
4 Waves
Exam-style questions
AQA Physics
d State one application, other than in education, of a polarising filter and give a
reason for its use.
(2 marks)
From AQA Physics A PHYA2 Mechanics, Materials and Waves June 2010
(Question 3)
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2
4 Waves
Exam-style questions
AQA Physics
2
Ultrasound waves are used to produce images of a foetus inside a womb.
a Explain what is meant by the frequency of a wave.
(1 mark)
b Ultrasound is a longitudinal wave. Describe the nature of a longitudinal wave.
(2 marks)
c
To produce an image with sufficient detail, the wavelength of the ultrasound
must be 0.50 mm. The speed of the ultrasound in body tissue is 1540 m s–1.
Calculate the frequency of the ultrasound at this wavelength.
Give your answer to an appropriate number of significant figures.
frequency
Hz
(2 marks)
From AQA Physics A PHYA2 Mechanics, Materials and Waves June 2014
(Question 7)
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This resource sheet may have been changed from the original
3
4 Waves
Exam-style questions
AQA Physics
3
Figure 3a shows a side view of a string on a guitar. The string cannot move at
either of the two bridges when it is vibrating. When vibrating at its first harmonic,
the frequency of the sound produced is 108 Hz.
a i On Figure 3a, sketch the stationary wave produced when the string is
vibrating at its first harmonic.
Figure 3a
ii
Calculate the wavelength of the first harmonic mode of vibration.
answer =
m
(2 marks)
iii Calculate the speed of a progressive wave on this string.
answer =
m s–1
(2 marks)
b While tuning the guitar, the guitarist produces a harmonic that has a node
0.16 m from bridge A.
i On Figure 3b, sketch the stationary wave produced and label all nodes
that are present.
Figure 3b
(2 marks)
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4
4 Waves
Exam-style questions
AQA Physics
ii
Calculate the frequency of the harmonic.
answer =
c
Hz
(1 mark)
The guitarist needs to raise the first harmonic frequency of vibration of this
string.
State one way in which this can be achieved.
(1 mark)
From AQA Physics A PHYA2 Mechanics, Materials and Waves January 2010
(Question 4)
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5
4 Waves
Exam-style questions
AQA Physics
4
Figure 4 shows two ways in which a wave can travel along a slinky spring.
Figure 4
a
State and explain which wave is longitudinal.
(2 marks)
b On Figure 4,
i clearly indicate and label the wavelength of wave B
(1 mark)
ii
use arrows to show the direction in which the points P and Q are about to
move as each wave moves to the right.
(2 marks)
c
Electromagnetic waves are similar in nature to wave A.
Explain why it is important to align the aerial of a television correctly to
receive the strongest signal.
(2 marks)
From AQA Physics A PHYA2 Mechanics, Materials and Waves June 2012
(Question 7)
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This resource sheet may have been changed from the original
6
4 Waves
Exam-style questions
AQA Physics
5
When a note is played on a violin, the sound it produces consists of the first
harmonic and many higher harmonics.
Figure 5a shows the shape of the string for a stationary wave that corresponds
to one of these higher harmonics. The positions of maximum and zero
displacement for one harmonic are shown. Points A and B are fixed. Points X, Y,
and Z are points on the string.
Figure 5a
a
i
Describe the motion of point X.
(2 marks)
ii
State the phase relationship between
X and Y
X and Z
(2 marks)
b The frequency of this harmonic is 780 Hz.
i Show that the speed of a progressive wave on this string is about 125 m s–1.
(2 marks)
ii
Calculate the time taken for the string at point Z to move from maximum
displacement back to zero displacement.
answer =
© Oxford University Press 2015
s
(3 marks)
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7
4 Waves
Exam-style questions
AQA Physics
c
The violinist presses on the string at C to shorten the part of the string that
vibrates.
Figure 5b shows the string between C and B vibrating at its first harmonic.
The length of the whole string is 320 mm and the distance between C and
B is 240 mm.
Figure 5b
i
State the name given to the point on the wave midway between C and B.
(1 mark)
ii
Calculate the wavelength of this stationary wave.
answer =
m
(2 marks)
iii Calculate the frequency of this first harmonic. The speed of the
progressive wave remains at 125 m s–1.
answer =
Hz
(1 mark)
From AQA Physics A PHYA2 Mechanics, Materials and Waves June 2012
(Question 6)
© Oxford University Press 2015
www.oxfordsecondary.co.uk/acknowledgements
This resource sheet may have been changed from the original
8