The Electromagnetic Spectrum
4 marks · NormalA hospital uses both X-rays and infrared cameras for patient care.
State the main property that all electromagnetic waves have in common.
Describe one use of infrared in hospitals, and one use of X-rays.
Explain why X-rays require more safety precautions than infrared when used with patients.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) They all transfer energy (or are all transverse waves).
(b) Infrared: used in cameras to detect body heat for monitoring temperature or for night-time observation. X-rays: used to take images of bones or internal structures.
(c) X-rays are ionising radiation and can damage cells/cause cancer, so more care is needed, unlike infrared which only causes heating or minor skin burns.
Also accept: all transfer energy; infrared: detecting heat from body, X-rays: imaging bones
Common mistakes: mixing up uses
Show mark scheme and worked solution
Marking points
A1 (a) · 1 mark · All electromagnetic waves transfer energy (or are transverse).
B1 (b) · 1 mark · States valid hospital use of infrared.
B2 (b) · 1 mark · States valid hospital use of X-rays.
C1 (c) · 1 mark · Explains X-rays are more dangerous/ionising/cause cell damage, so more precautions are essential.
Worked solution
(a) All electromagnetic waves transfer energy.
(b) Infrared cameras are used to detect temperature or heat loss in the body. X-rays are used to produce images of bones or check for fractures.
(c) X-rays are ionising and can cause cancer by damaging living cells, so staff must use lead shields and minimise exposure. Infrared is not dangerous unless very intense.