CIE A Level Physics

Topic Questions

Syllabus Edition

First teaching 2020

Last exams 2024

|

7.2 Transverse Waves: EM Spectrum & Polarisation

11 mark

The following are statements about waves. Which statement below describes a situation in which polarisation would not happen?

  • microwaves pass through a metal grid

  • sound waves pass through a metal grid

  • light waves are reflected

  • light waves are scattered

Did this page help you?

21 mark

A student looked at the liquid crystal display on their calculator with a polarising film. They observed that as they rotated the film, the display changed.

 Which property of the radiation from the calculator display is described correctly?

  • the emitted radiation is a transverse wave

  • the emitted radiation is a wave with 3 cm wavelength

  • the emitted radiation is unpolarised

  • the emitted radiation is a longitudinal wave

Did this page help you?

31 mark

Which of the following is the approximate range of frequencies of infrared radiation?

  • 1 × 1014 – 1 × 1016 Hz

  • 1 × 1012 – 1 × 1014 Hz

  • 1 × 109 – 1 × 1011 Hz

  • 1 × 103 – 1 × 109 Hz

Did this page help you?

41 mark

Which of the following waves can be polarised?

  • transverse

  • progressive

  • stationary

  • longitudinal

Did this page help you?

51 mark

Which of the following statement is a correct description of part of the electromagnetic spectrum?

  • waves of wavelength 5 × 10–7 m are infrared waves

  • waves of wavelength 5 × 10–9 m are high energy gamma rays

  • waves of wavelength 9 × 10–7 m are light waves

  • waves of wavelength 3 × 10–8 m are ultraviolet waves

Did this page help you?

61 mark

Which of the following give the order of magnitude of frequencies of the visible part of the electromagnetic spectrum?

  • 1015 Hz

  • 1014 Hz

  • 1013 Hz

  • 1016 Hz

Did this page help you?

71 mark

Malus’s law shows the intensity of polarised light as it emerges through an analyser. Which is the correct equation to calculate the intensity?

  • I subscript 0 sin squared theta

  • I subscript 0 space cos squared space theta

  • I subscript 0 cos space theta

  • I subscript 0 over 2 space cos squared space theta

Did this page help you?

81 mark

The diagram shows part of the electromagnetic spectrum.

cie-ial-images344png

Which row correctly labels the regions marked P and Q?

 

P

Q

A

B

C

D

infrared

ultraviolet

x-ray

infrared

x-ray

x-ray

infrared

microwaves

Did this page help you?

91 mark

Which of the following do not travel at the speed of light in a vacuum?

  • x-rays

  • radio waves

  • microwaves

  • electrons

Did this page help you?

101 mark

Which of the following is the number of wavelengths in one metre of visible light?

  • 104

  • 106

  • 108

  • 1010

Did this page help you?

11 mark

A beam of unpolarised light is incident on the first of two parallel polarisers. The transmission axis of the two polarisers are initially parallel.

The first polariser is now rotated about the direction of the incident beam by an angle smaller than 90°.

 Which row in the table describes the changes to the intensity and polarisation of the transmitted light?

 

Intensity

Polarisation

A

B

C

D

no change

no change

different

different

no change

different

different

no change

Did this page help you?

21 mark

Unpolarised light is incident on the surface of a transparent medium. The reflected light is completely plane polarised.

 Which option correctly describes the refracted light?

  • partially plane polarised

  • completely plane polarised parallel to the reflected light

  • unpolarised

  • completely plane polarised at right angles to the reflected light

Did this page help you?

31 mark

Unpolarised light of intensity I0 is incident on a polariser that has a vertical transmission axis, as shown in the diagram below.

cie-ial-images351png

Which graph shows the intensity of the transmitted light ?

cie-ial-physics-mcq-7-2-q23

Did this page help you?

41 mark

Plane-polarised light of amplitude a is passed through a polarising filter. The amplitude of the light emerging is a cos θ.

 The intensity of the incident ray is I

 What is the intensity of the emerging light when θ is 60˚?

  • 0.866 I

  • 0.750 I

  • 0.500 I

  • 0.250 I

Did this page help you?

51 mark

A person wearing polarising sunglasses stands at the edge of a pond in bright sunlight.

cie-ial-images356png

The surface of the pond is flat, and the person has a line of sight to the surface of angle θ. The refractive index of the pond water is n.

 What is the value of θ for which the light would be a minimum when it reaches the persons eye?

  • tan to the power of negative 1 end exponent open parentheses 1 over n close parentheses

  • cos to the power of negative 1 end exponent open parentheses 1 over n close parentheses

  • tan to the power of negative 1 end exponent open parentheses n close parentheses

  • cos to the power of negative 1 end exponent open parentheses n close parentheses

Did this page help you?

61 mark

Unpolarised light is incident on a polariser. The light transmitted by the first polariser is then incident on a second polariser. The polarising axis of the second sheet is 60˚ to that of the first.

 The intensity emerging from the second polariser is I2.

 Which of the following gives the intensity incident on the first polariser?

  • I subscript 2 over 4

  • I subscript 2 over 8

  • 8 I subscript 2

  • 4 I subscript 2

Did this page help you?

71 mark

A vertical aerial transmits radio waves that have been plane-polarised. The receiving aerial is tilted from the vertical at an angle θ. The emitted wave is in a plane perpendicular to the direction of arrival and arrive with an amplitude A.

 Which of the following expressions is proportional to the power delivered by the aerial?

  •  A space cos space theta

  • A squared space c o s to the power of 2 space end exponent theta

  • Z e r o

  • A squared space sin squared space theta

Did this page help you?

81 mark

Unpolarised light of intensity I0 is incident on the first of two polarising sheets. Initially the planes of polarisation of the sheets are perpendicular.

 Which sheet must be rotated and by what angle θ, so that light intensity  I subscript 0 over 4   can emerge from the second sheet ?

 

Rotated sheet

Angle θ of rotation

A

1 or 2

cos to the power of negative 1 end exponent 1 half

B

1 or 2

cos to the power of negative 1 end exponent fraction numerator square root of 2 over denominator 2 end fraction

C

2 only

cos to the power of 1 space 1 half

D

1 only

cos to the power of negative 1 end exponent fraction numerator square root of 2 over denominator 2 end fraction

Did this page help you?

91 mark

The diagram below shows a ray of unpolarised light with an intensity of 72 W m−2 passing through three polarising films, P1, P2 and P3.

 cie-ial-images359png

The polarising axis of each polarising film is shown by an arrow. The polarising film P1 and P2 are fixed, with their axis of polarisation at 30˚ to one each other.

 If the light emerging from the third filter has an intensity of 13.5 W m−2 what is angle θ ?

  • 60°

  • 90°

  • 30°

  • 45°

Did this page help you?

101 mark

The angle between a polariser and analyser is 30°. The intensity of light transmitted by the analyser is greater that the intensity transmitted by the polariser.

 How much smaller is the intensity transmitted?

  • 1 half

  • 3 over 4

  • 1 fourth

  • 0

Did this page help you?

11 mark

Two lasers are set up to pass through a vacuum. One laser emits red light; the other emits green light.

 Which property of the two lasers are different?

  • speed

  • plane of polarisation

  • frequency

  • amplitude

Did this page help you?

21 mark

The wavelength of light emitted by a laser is 600 nm.

 Which of the following is the distance in number of wavelengths, that is travelled by light in one second?

  • 5.0 × 1014 s–1

  • 5.0 × 108 s–1

  • 5.0 × 1011 s–1

  • 5.0 × 1017 s–1

Did this page help you?

31 mark

Waves of the electromagnetic spectrum travel through a vacuum at speed c and with a wavelength λ and frequency f

 Which of the following describes the speed and wavelength when the frequency is f over 2  ?

 

λ

c

A

2 lambda 2 c

B

2 lambda c

C

lambda over 2 c

D

lambda over 2 c over 2

Did this page help you?

41 mark

The diameter of a nucleus and the wavelength of an electromagnetic wave are in the same order of magnitude.

 In which region of the electromagnetic spectrum would that wavelength occur?

  • infrared

  • visible light

  • x-ray

  • gamma-ray

Did this page help you?

51 mark

R is a source emitting infra-red radiation and S is a source emitting ultra-violet radiation. The table suggests the wavelengths for R and S.

 Which row is correct?

 

Wavelength emitted by R / m

Wavelength emitted by S / m

A

B

C

D

5 × 10–7

5 × 10–8

5 × 10–5

5 × 10–5

5 × 10–8

5 × 10–10

5 × 10–8

5 × 10–10

Did this page help you?

61 mark

Which statement would be deduced from a table of wavelengths of the waves in the electromagnetic spectrum?

  • the wavelength range for radio waves is less than that for infrared waves

  • the wavelength range for x-rays is less than that for radio waves

  • red light has a shorter wavelength than green light

  • green light has a shorter wavelength than x-rays

Did this page help you?

71 mark

A telescope detects electromagnetic radiation with wavelengths 2 cm.

Which type of telescope is it ?

  • x-ray telescope

  • optical telescope

  • microwave telescope

  • radio telescope

Did this page help you?

81 mark

A linearly polarised electromagnetic beam has an intensity of 16 W m2 with an angle of incidence of 45° to the vertical.

 What is the intensity of the transmitted beam?

  • 20 W m–2

  • 12 W m–2

  • 16 W m–2

  • 8 W m–2

Did this page help you?

91 mark

Unpolarised light of intensity I0 is incident on a polariser with a vertical transmission axis. The transmitted light is incident on a sheet of material X. After transmission through X the intensity of light is I subscript 0 over 2

 It is suggested that X could be

1

a polariser with a vertical transmission axis

2

a polariser with a horizontal transmission axis

3

non-polarising glass

  • 1 & 2

  • 2 & 3

  • 1 & 3

  • 3 only

Did this page help you?

101 mark

The quality of the sound produced by a portable radio can be improved by changing the orientation of the aerial.

 Which statement will correctly describe the explanation of this improvement?

  • the radio waves become polarised as a result of adjusting the aerial

  • the radio waves become unpolarised as a result of adjusting the aerial

  • the radio waves from the transmitter are unpolarised

  • the radio waves from the transmitter are polarised

Did this page help you?