Practise EM waves: production and hazards. 13 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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Give one harmful effect of ultraviolet radiation on the skin.
It increases the risk of skin cancer (or causes premature ageing of the skin).
What is meant by ionising radiation?
Radiation that can knock electrons out of atoms, forming ions.
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Some types of electromagnetic radiation can be hazardous to human body tissue.
(a) Which two types of electromagnetic radiation are ionising? Tick (✓) two boxes.[2]
Gamma rays
Infrared
Microwaves
Visible light
X-rays
(b) Give one harmful effect of ultraviolet radiation on the skin.[1]
(c) Gamma rays are produced by changes in one part of an atom. Which part? Tick (✓) one box.[1]
The electrons
The nucleus
The outer shell
(d) Give one harmful effect of X-rays on body tissue.[1]
Show the answer and mark scheme
(a)Answer: Gamma rays; X-rays
(b)Answer: It increases the risk of skin cancer (or causes premature ageing of the skin).
makes the skin age prematurely / increases the risk of skin cancer
(c)Answer: The nucleus
(d)Answer: They can cause mutation of genes, leading to cancer.
mutation of genes / cancer
Question 2Medium8 marks
A sunbed uses lamps that emit ultraviolet radiation to tan the skin.
(a) Give two risks of using a sunbed.[2]
(b) A leaflet states that 10 minutes on a sunbed gives about the same ultraviolet dose as 1 hour in strong midday sunshine. A person uses the sunbed for 25 minutes, twice a week. Calculate the number of hours of strong midday sunshine that give the same ultraviolet dose as one week of these sunbed sessions.[2]
(c) Some sun creams absorb ultraviolet radiation. Explain how using this type of sun cream reduces the risk of harm.[2]
(d) A radiographer takes many X-ray images each day. The radiographer stands behind a lead screen when the X-ray machine is switched on. Explain why.[2]
Show the answer and mark scheme
(a)Answer: Premature ageing of the skin and an increased risk of skin cancer.
the skin ages prematurely
increased risk of skin cancer
(b)Answer: 5 hours
time on sunbed each week = 2 × 25 = 50 minutes
50 ÷ 10 × 1 = 5 (hours)
(c)Answer: The cream absorbs ultraviolet, so less reaches the skin and the dose is smaller.
less ultraviolet reaches / is absorbed by the skin (cells)
so the dose to the skin is smaller
(d)Answer: The lead absorbs X-rays; without it the radiographer's dose would build up over many images and increase the risk of cancer.
lead absorbs X-rays, so the radiographer's dose is reduced
the dose from many X-rays each day would add up, increasing the risk of gene mutation / cancer
Question 3Hard8 marks
A radio transmitter produces radio waves with a frequency of 1.2 MHz. An aerial on a radio receiver absorbs some of these radio waves. The speed of radio waves is 3.0 × 108 m/s.
(a) Describe how the radio waves are produced by the transmitter.[2]
(b) Describe the effect of the radio waves on the aerial of the receiver.[2]
(c) Calculate the period of the alternating current in the receiving aerial. Use the Physics Equations Sheet.[2]
(d) Calculate the wavelength of the radio waves.[2]
Show the answer and mark scheme
(a)Answer: An alternating current (oscillating charges) in the transmitter circuit produces radio waves of the same frequency.
oscillations (of electrons / charges) in an electrical circuit / an alternating current in the transmitting aerial
produce radio waves with the same frequency as the oscillations
(b)Answer: They induce an alternating current in the aerial with the same frequency as the waves.
the radio waves are absorbed and create / induce an alternating current in the aerial
with the same frequency as the radio waves (1.2 MHz)