Electromagnetic spectrum
3.3What the syllabus asks of you
- Know the main regions of the electromagnetic spectrum in order of frequency and in order of wavelength
- Know that the speed of all electromagnetic waves in: (a) a vacuum is 3.0 × 108 m / s (b) air is approximately the same as in a vacuum
- Describe the role of the following components in the stated applications: (a) radio waves – radio and television communications, astronomy (b) microwaves – satellite television, mobile (cell) phone, Bluetooth, microwave ovens (c) infrared – household electrical appliances, remote controllers, intruder alarms, thermal imaging, optical fibres (d) visible light – photography, vision (e) ultraviolet – security marking, detecting counterfeit bank notes, sterilising water (f) X-rays – hospital use in medical imaging, security scanners, killing cancerous cells, engineering applications such as detecting cracks in metal (g) gamma rays – medical treatment in detecting and killing cancerous cells, sterilising food and medical equipment, engineering applications such as detecting cracks in metal
- Describe the damage caused by electromagnetic radiation, including: (a) excessive exposure causing heating of soft tissues and burns (b) ionising effects caused by ultraviolet (skin cancer and cataracts), X-rays and gamma rays (cell mutation and cancer)
Read the notes first
Chapter 3: Electromagnetic spectrum
Drill this topic
Every question on Electromagnetic spectrum, untimed, marked as you go.
Make a worksheet
Choose the years and how many questions, then print it with the answers on separate pages.
26 questions
1May / June 2026 · Paper 11 · Q28Show mark scheme →
AGamma rays have a longer wavelength than ultraviolet waves.
BInfrared waves have a lower frequency than radio waves.
CMicrowaves have a longer wavelength than visible light.
DX-rays have a higher speed in air than visible light.
Mark scheme
2May / June 2026 · Paper 12 · Q27Show mark scheme →
AUltraviolet waves have a greater speed in air than radio waves.
BUltraviolet waves have longer wavelengths than radio waves.
CUltraviolet waves have lower frequencies than radio waves.
DUltraviolet waves are ionising, but radio waves are not ionising.
Mark scheme
3Oct / Nov 2024 · Paper 11 · Q27Show mark scheme →
A1 and 3
B2, 3 and 4
C2 only
D3 and 4 only
Mark scheme
4Oct / Nov 2024 · Paper 12 · Q23Show mark scheme →
Alight and sound
Bultrasound and ultraviolet
Cwater waves and infrared
DX-rays and microwaves
Mark scheme
5May / June 2024 · Paper 11 · Q27Show mark scheme →
Ainfrared | microwave
Binfrared | ultraviolet
Clight | microwave
Dlight | ultraviolet
Mark scheme
6May / June 2024 · Paper 12 · Q22Show mark scheme →
AIn a vacuum, infrared radiation travels at the speed of light.
BInfrared radiation is a longitudinal wave.
CInfrared radiation has a higher frequency than ultraviolet radiation.
DWhite surfaces are better emitters of infrared radiation than black surfaces.
Mark scheme
7Oct / Nov 2023 · Paper 12 · Q30Show mark scheme →
ABluetooth technology
Bprenatal scanning
Csterilising water
Dthermal imaging
Mark scheme
8May / June 2023 · Paper 11 · Q23Show mark scheme →
Ainfrared | ultraviolet
Bmicrowave | radio
Cradio | microwave
Dultraviolet | infrared
Mark scheme
9Oct / Nov 2022 · Paper 12 · Q26Show mark scheme →
Amobile phone
Bsunbed
Ctelevision controller
Dtoaster
Mark scheme
10May / June 2022 · Paper 11 · Q23Show mark scheme →
Aradio waves
Btelevision signals
Cultrasound
Dultraviolet
Mark scheme
11Oct / Nov 2021 · Paper 11 · Q24Show mark scheme →
Agamma rays
Binfrared rays
Cradio waves
Dultraviolet rays
Mark scheme
12Oct / Nov 2021 · Paper 12 · Q27Show mark scheme →
A1.0 × 10^–6 s
B2.0 × 10^–6 s
C1.0 × 10^–3 s
D2.0 × 10^–3 s
Mark scheme
13May / June 2021 · Paper 12 · Q27Show mark scheme →
Alight and sound
Bwater waves and infrared
Cultrasound and ultraviolet
DX-rays and microwaves
Mark scheme
14Oct / Nov 2020 · Paper 12 · Q25Show mark scheme →
Amobile phone | fluorescent tube | intruder alarm
Bkilling cancerous cells | sterilising surgical instruments | satellite television
Cmedical imaging | television controller | sunbed
Dsterilising surgical instruments | television controller | detecting cracks in metal
Mark scheme
15May / June 2020 · Paper 11 · Q29Show mark scheme →
AA prism deviates red light more.
BRed light has a lower frequency.
CRed light has a shorter wavelength.
DThe speed of red light in a vacuum is smaller.
Mark scheme
16Oct / Nov 2019 · Paper 11 · Q25Show mark scheme →
Afrequency / Hz: 3.0 × 10^5; speed in air m / s: 1500
Bfrequency / Hz: 3.0 × 10^5; speed in air m / s: 3.0 × 10^8
Cfrequency / Hz: 3.0 × 10^14; speed in air m / s: 1500
Dfrequency / Hz: 3.0 × 10^14; speed in air m / s: 3.0 × 10^8
Mark scheme
17Oct / Nov 2018 · Paper 12 · Q26Show mark scheme →
ARadio waves are sound waves.
BRadio waves are used to kill cancerous cells.
CRadio waves are used in television communications.
DRadio waves have frequencies higher than those of visible light.
Mark scheme
18May / June 2018 · Paper 11 · Q1Show mark scheme →
AAll electromagnetic waves have speeds in air of approximately 3 × 10^8 m / s.
BIn air, some electromagnetic waves travel faster than light.
CThe electromagnetic waves with the largest wavelength are in the infra-red region.
DThe electromagnetic waves with the smallest wavelength are in the X-ray region.
Mark scheme
19May / June 2018 · Paper 12 · Q30Show mark scheme →
AIt causes ionisation.
BIt consists of longitudinal waves.
CIt has a higher frequency than ultra-violet light.
DIt travels at the speed of light.
Mark scheme
20Oct / Nov 2017 · Paper 11 · Q23Show mark scheme →
Agamma rays
Binfra-red
Clight
Dradio waves
Mark scheme
21Oct / Nov 2017 · Paper 12 · Q24Show mark scheme →
AA
BB
CC
DD
Mark scheme
22May / June 2017 · Paper 11 · Q29Show mark scheme →
Ainfra-red visible light microwave
Bmicrowave infra-red visible light
Cvisible light infra-red microwave
Dvisible light microwave infra-red
Mark scheme
23May / June 2017 · Paper 12 · Q29Also set in May / June 2017 Paper 11Show mark scheme →
Ainfra-red waves
Blight waves
Cmicrowaves
Dsound waves
Mark scheme
24Oct / Nov 2016 · Paper 11 · Q28Show mark scheme →
Agamma-rays and microwaves
Bgamma-rays and X-rays
Cmicrowaves and ultra-violet radiation
Dultra-violet radiation and X-rays
Mark scheme
25May / June 2016 · Paper 11 · Q24Show mark scheme →
AThey have a longer wavelength than radio waves.
BThey penetrate the atmosphere without significant loss of energy.
CThey travel much faster than radio waves in a vacuum.
DThey warm the satellite and stop it freezing.
Mark scheme
26May / June 2016 · Paper 11 · Q25Show mark scheme →
Ain fluorescent tubes
Bin killing cancerous cells
Cin pre-natal scanning
Din sunbeds
Mark scheme