Electromagnetic Waves Practice Questions

Question 1

5 marks

The electromagnetic spectrum is a continuous spectrum of waves.

(a)

The list below shows the groups of the electromagnetic spectrum in order of increasing frequency. Three groups are missing.

radio waves → A → infrared → visible light → B → X-rays → C

Name the groups A, B and C.

/ 2

(b)

Give two properties that all electromagnetic waves have in common.

/ 2

(c)

A hot radiator emits infrared radiation, but a person cannot see the infrared radiation.

Explain why.

/ 1

Question 2

4 marks

Different groups of electromagnetic waves have different practical applications.

(a)

Give one use of microwaves, other than cooking food.

/ 1

(b)

Give one use of infrared radiation.

/ 1

(c)

Give one use of X-rays.

/ 1

(d)

Which group of electromagnetic waves is produced by changes in the nucleus of an atom?

/ 1

Question 3

3 marks

Table 1 gives the wavelengths of four electromagnetic waves.

Table 1

Wave	Wavelength
P	25 µm
Q	0.05 nm
R	500 nm
S	3 cm

(a)

Which of the following is equal to the wavelength of wave P?

Tick (✓) one box.

$2.5 \times 10^{5}$ m
$2.5 \times 10^{-5}$ m
$2.5 \times 10^{-6}$ m
$2.5 \times 10^{-9}$ m

/ 1

(b)

Which wave, P, Q, R or S, has the highest frequency?

Give a reason for your answer.

/ 1

(c)

Name the group of the electromagnetic spectrum that wave S belongs to.

/ 1

Question 0

6 marks

A wireless router in a house transmits microwaves with a frequency of 2.4 GHz.

Electromagnetic waves travel at $3.0 \times 10^{8}$ m/s in air.

(a)

Write 2.4 GHz in hertz. Give your answer in standard form.

/ 1

(b)

Calculate the wavelength of the microwaves transmitted by the router.

Use the equation:

$\text{wave speed} = \text{frequency} \times \text{wavelength}$

/ 3

(c)

A television signal is broadcast at a frequency of 600 MHz.

Calculate the wavelength of this signal.

/ 2

Question 0

6 marks

A student used a Leslie cube to investigate how the infrared radiation emitted by a surface depends on the nature of that surface.

The four vertical faces of the cube had different surfaces. The cube was filled with hot water. An infrared detector was placed in front of each face in turn and the reading was recorded.

Table 2

Surface of cube face	Infrared detector reading in arbitrary units
Matt black	30
Shiny black	24
Matt white	21
Shiny silver	10

(a)

Name the dependent variable in this investigation.

/ 1

(b)

Give two variables that the student should have controlled in this investigation.

/ 2

(c)

Write a conclusion for this investigation. Use data from Table 2 in your answer.

/ 2

(d)

Describe how the student could check that the results are repeatable.

/ 1

Question 0

5 marks

Figure 1 shows a ray of light travelling through air towards a rectangular glass block. The normal at the point where the ray meets the block is shown as a dashed line.

Figure 1

(a)

Complete Figure 1 to show the path of the ray of light through the glass block and after it leaves the block.

/ 2

(b)

Explain, in terms of the speed of light, why the ray changes direction as it enters the glass.

/ 2

(c)

A second ray of light enters the glass block along the normal.

State what happens to the direction of this ray as it enters the glass.

/ 1

Question 0

6 marks

Radiation dose is measured in sieverts (Sv). Table 3 gives typical radiation doses in millisieverts (mSv).

Table 3

Source of exposure	Typical dose in mSv
One dental X-ray	0.005
One chest X-ray	0.02
One CT scan of the chest	7.0
Average background radiation in the UK in one year	2.7

(a)

State what radiation dose, measured in sieverts, is a measure of.

/ 1

(b)

Calculate the number of chest X-rays that would give the same total radiation dose as one CT scan of the chest.

/ 2

(c)

A hospital radiographer takes many X-ray images each day. The radiographer stands behind a lead screen each time an X-ray image is taken.

Explain why.

/ 2

(d)

State one harmful effect of ultraviolet radiation on the skin.

/ 1

Question 0

6 marks

Figure 2 shows the wave fronts of a beam of light crossing the boundary from air into glass. The arrows show the direction in which the light travels.

Figure 2

(a)

Explain, using Figure 2, why the light changes direction as it crosses the boundary from air into glass.

/ 3

(b)

State what happens to the frequency of the light as it crosses the boundary into the glass.

/ 1

(c)

The light has a frequency of $5.0 \times 10^{14}$ Hz. In the glass the light travels at a speed of $2.0 \times 10^{8}$ m/s.

Calculate the wavelength of the light in the glass.

/ 2

Question 0

6 marks

A local radio station broadcasts on a frequency of 96 MHz. The transmitter contains an electrical circuit in which charges oscillate.

(a)

Explain how the transmitter produces radio waves.

/ 2

(b)

A radio in a house several kilometres away picks up the broadcast using an aerial.

State the frequency of the current produced in the aerial and explain your answer.

/ 2

(c)

Suggest two reasons why radio waves, rather than X-rays, are used to broadcast programmes to homes.

/ 2

Energy

Electricity

Particle Model of Matter

Atomic Structure

Forces

Waves

Magnetism & Electromagnetism

Space Physics

Question 1

Question 2

Question 3

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