An aquarium education centre is choosing radiation for three tasks. The types being considered are visible light, infrared, ultraviolet and microwaves.
P: ultraviolet to sterilise the surfaces of empty tanks
Q: microwaves to operate an exhibit using a handheld remote control
R: visible light to take colour photographs of fish
Which single change would make every choice suitable?
Use infrared instead of ultraviolet for task P.
Use ultraviolet instead of visible light for task R.
Use infrared instead of visible light for task R.
Use infrared instead of microwaves for task Q.
104 exam-style questions on Edexcel GCSE Physics 5.4 Uses and dangers of EM radiation, covering 5.4.1 Dangers of electromagnetic radiation, 5.4.2 Uses of electromagnetic radiation, 5.4.3 Radio waves and oscillations in circuits, and 5.4.4 Changes in atoms and nuclei generating radiation. Each one has a worked solution and a mark scheme showing where the marks go.