Waves Foundation Tier Questions
Q1 This diagram shows an endoscope which can
be used to examine the inside of narrow tubes or
pipes.
Objective
lens
glass (optical) fibres
Image tube
Pipe
lens
Light tube
LAMP
Explain, in as much detail as you can, how an
engineer is able to see the inside of the pipe.
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1 Answer

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idea that
light stays inside the glass fibre/
travels down light tube
because of repeated reflection (off side of fibres)
total internal reflection
lens at end of light tube focuses light on object
light reflected along the image tube to objective
camera/eye placed at objective
focusing needed for clear image
any six for 1 mark each
[6]
Q2 A man is walking along the bank of a river. He
sees a fish which seems to be at X.
(a) Show, on the diagram, where the fish really is.
Complete the ray of light which goes from the
fish into the man’s eye. [2]
(b) Complete the sentence.
The ray of light is ........................................ as it
passes from the water into the air. [1]
Total 3 marks
2 Answer
(a)
 line (from fish) to complete ray to eye
[mark awarded even if begins outside the box]
[credit only if fish shown to left of normal]
 fish within the region shown or X or start of ray
 not necessarily directly below x)
 each for 1 mark
x
(b) bent/refracted/deviated/speeded up 1
for 1 mark
[3]
Q3 The diagram shows some waves travelling
along a rope.
rope attached
to wall
(a) Show on the diagram
(i) the wavelength of one of the waves [2]
(ii) the amplitude of one of the waves [2]
(b) The waves shown on the diagram were
produced in two seconds. What is the frequency of
the waves?
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.......................................[2]
Total 6 marks
3 Answer
(a) (i)
mark]
a horizontal distance indicated and labelled [1
but; horizontal distance indicated between identical points
on adjacent waves (to within 3-4mm) and labelled [2
marks]
(ii)
peak to middle or middle to trough indicated [1 mark]
but peak / trough to mean indicated to within 1-2mm
either end [2 marks]
(allow 1 mark if both lines unlabelled or 2 marks if both
lines accurately drawn and unlabelled)
(b) 1.5 hertz / 1.5 Hz
per second
or
1.5
(waves / cycles)
for 1 mark each
(do not allow wavelength / hertz per second)
[6]
Q4 Doctors use optical fibres to see inside your
stomach. The diagram shows a ray of light travelling
through an optical fibre.
air
glass
ray of light
(a) What happens to the ray of light each time it
strikes the boundary between the glass and the air?
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(b) Complete the following sentence. The ray of
light stays inside the optical fibre. This happens
because the angle between the ray and each
normal is....................................................................
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Total 4 marks
4 Answer
(a) reflected / bounces off [1 mark]
but all / totally reflected [2 marks]
(b) large or specified angle > 42° or any reference
to critical angle [1 mark]
but greater than critical angle / greater than 42°
[2 marks]
[4]