GCSE PhysicsAQA, Edexcel and OCR
27 physics questions on light and electromagnetic waves. Pick your answer, then tap to see if you were right and why. Every answer comes from the Show Working science bank, checked against the GCSE content every board in England teaches.
01 / Quiz yourselfTry it, then tap to check
Choose your answer before you open it. Then read why, so it sticks.
01 / Light and electromagnetic wavesBoth tiers
Answer: C An electromagnetic wave
Light is one part of the electromagnetic spectrum, the visible part. Like all electromagnetic waves it is transverse and can travel through empty space, which is how sunlight reaches us.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.1 Types of electromagnetic waves
02 / Light and electromagnetic wavesBoth tiers
Answer: A Transverse waves that can travel through a vacuum
All electromagnetic waves are transverse and travel through a vacuum (space) at the same, very high speed. They differ in wavelength and frequency, not in their speed in a vacuum.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.1 Types of electromagnetic waves
03 / Light and electromagnetic wavesBoth tiers
Answer: B The Sun warming your skin
Electromagnetic waves carry energy from a source to an absorber. Infrared from the Sun warms your skin, microwaves warm food, and radio waves give energy to an aerial. No material travels with the waves.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.1 Types of electromagnetic waves
04 / Light and electromagnetic wavesBoth tiers
The right order:
From long wavelength and low frequency to short wavelength and high frequency, the groups are: radio waves, microwaves, infrared, visible light (red to violet), ultraviolet, X-rays and gamma rays. It is one continuous spectrum.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.1 Types of electromagnetic waves
05 / Light and electromagnetic wavesBoth tiers
Answer: B Radio waves
Radio waves have the longest wavelength and the lowest frequency; gamma rays have the shortest wavelength and the highest frequency. As wavelength gets shorter along the spectrum, frequency gets higher.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.1 Types of electromagnetic waves
06 / Light and electromagnetic wavesBoth tiers
Answer: C Infrared
Infrared sits just beyond red light, on the long wavelength side of the visible spectrum. Ultraviolet sits just beyond violet, on the short wavelength side, before X-rays.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.1 Types of electromagnetic waves
07 / Light and electromagnetic wavesBoth tiers
Answer: A Red
Our eyes detect only a small part of the spectrum, visible light, from red (longest wavelength, lowest frequency) to violet (shortest wavelength, highest frequency). Everything else in the spectrum is invisible to us.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.1 Types of electromagnetic waves
08 / Light and electromagnetic wavesHigher only
Answer: B It slows down in the glass
Refraction happens because waves travel at different speeds in different substances. Light slows down when it enters glass from air, so if it meets the surface at an angle it bends towards the normal.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.2 Properties of electromagnetic waves 1
09 / Light and electromagnetic wavesHigher only
Answer: B How a substance affects a wave depends on its wavelength
A substance can absorb, transmit, refract or reflect electromagnetic waves, and what it does depends on the wavelength. A brick wall absorbs or reflects visible light but transmits many radio waves.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.2 Properties of electromagnetic waves 1
10 / Light and electromagnetic wavesHigher only
Answer: B By oscillations in electrical circuits
Oscillating currents in an electrical circuit produce radio waves. When radio waves are absorbed by an aerial, they can induce an alternating current in it with the same frequency as the radio wave, which is how a radio receiver picks them up.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.3 Properties of electromagnetic waves 2
11 / Light and electromagnetic wavesBoth tiers
Answer: B Changes in the nucleus of an atom
Changes in atoms and their nuclei can give out or absorb electromagnetic radiation over a wide range of frequencies. When electrons drop to lower energy levels, radiation such as light is emitted. Gamma rays come from changes inside the nucleus.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.3 Properties of electromagnetic waves 2
12 / Light and electromagnetic wavesBoth tiers
Answer: C Radio waves
Radio waves are used for radio and television broadcasts. Microwaves pass through the atmosphere well, so they are used for satellite communications, and they are absorbed by water in food, so they are used for cooking.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.4 Uses and applications of electromagnetic waves
13 / Light and electromagnetic wavesBoth tiers
Answer: D Infrared
All objects give out infrared, and hotter objects give out more, so infrared cameras can show differences in temperature. Electric heaters warm us with infrared. Ordinary cameras, like our eyes, use visible light.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.4 Uses and applications of electromagnetic waves
14 / Light and electromagnetic wavesBoth tiers
Answer: D Energy efficient (fluorescent) lamps
Ultraviolet makes the coating inside fluorescent lamps glow. X-rays pass through soft tissue but are absorbed by bone, so they show bones. X-rays and gamma rays carry a lot of energy, so they are used in medical imaging and to treat cancer.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.4 Uses and applications of electromagnetic waves
15 / Light and electromagnetic wavesBoth tiers
Answer: B Bone absorbs X-rays more than soft tissue does
X-rays pass easily through skin and muscle but are absorbed by dense bone. The detector behind the body receives fewer X-rays where there is bone, so bones show up clearly on the image.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.4 Uses and applications of electromagnetic waves
16 / Light and electromagnetic wavesBoth tiers
Answer: A Age the skin and increase the risk of skin cancer
Ultraviolet can age skin early and raise the risk of skin cancer. X-rays and gamma rays are ionising: they can damage cells and cause mutations in genes, which can lead to cancer. Being exposed to them does not make you radioactive.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.3 Properties of electromagnetic waves 2
17 / Light and electromagnetic wavesBoth tiers
Answer: C Ultraviolet, X-rays and gamma rays
The higher the frequency of an electromagnetic wave, the more energy it carries and the more harm it can do. Ultraviolet, X-rays and gamma rays are the hazardous end of the spectrum; gamma rays pass deep into the body.
Checked against DfE GCSE single science subject content (gov.uk), physics: Light and electromagnetic waves (uses and hazardous effects)
18 / Light and electromagnetic wavesBoth tiers · separate only
Answer: A The angle of incidence equals the angle of reflection
When light reflects from a mirror, the angle of incidence equals the angle of reflection. Both angles are measured from the normal, the line drawn at right angles to the surface where the ray hits it.
Checked against AQA GCSE Physics 8463 specification, 4.6.1.3 Reflection of waves
19 / Light and electromagnetic wavesBoth tiers · separate only
Answer: A By refracting light
A lens changes the direction of light by refraction. Parallel rays meet at (or seem to come from) the principal focus, and the distance from the lens to it is the focal length. A real image can be shown on a screen; a virtual image cannot.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.5 Lenses (physics only)
20 / Light and electromagnetic wavesBoth tiers · separate only
Answer: D It reflects red light and absorbs the other colours
An opaque object’s colour is the colour it reflects most; it absorbs the rest. A white object reflects all colours and a black one absorbs them all. Blue light on a red shirt is absorbed, nothing is reflected, so it looks black.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.6 Visible light (physics only)
21 / Light and electromagnetic wavesBoth tiers · separate only
Answer: C It transmits red light and absorbs other colours
A filter does not add colour. It lets some wavelengths through (transmits them) and absorbs the rest. A green filter in white light lets only the green part through.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.6 Visible light (physics only)
22 / Light and electromagnetic wavesBoth tiers · separate only
Answer: A Specular reflection
A smooth surface such as a mirror gives specular reflection: the light leaves in one direction, so you see an image. A rough surface scatters the light in many directions (diffuse reflection). Translucent materials let light through but scatter it, unlike transparent ones.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.6 Visible light (physics only)
23 / Light and electromagnetic wavesBoth tiers · separate only
Answer: C All objects, whatever their temperature
Every object emits radiation, even a cold one. The hotter it is, the more radiation it gives out each second, and the shorter the wavelength of its strongest emission. That is why a heated metal glows red, then yellow, then white.
Checked against AQA GCSE Physics 8463 specification, 4.6.3 Black body radiation (physics only)
24 / Light and electromagnetic wavesBoth tiers
Answer: B Matt black
Dark, matt surfaces are the best absorbers and the best emitters of infrared. Light, shiny surfaces are poor emitters and reflect infrared well, so a shiny silver can keeps water hot longest.
Checked against AQA GCSE Physics 8463 specification, Required practical 10, infrared radiation and surfaces
25 / Light and electromagnetic wavesHigher only · separate only
Answer: B It absorbs radiation at the same rate as it emits it
An object’s temperature stays the same when it absorbs radiation at the same rate as it emits it. If it absorbs faster than it emits, it warms up; if it emits faster than it absorbs, it cools down.
Checked against AQA GCSE Physics 8463 specification, 4.6.3 Black body radiation (physics only)
26 / Light and electromagnetic wavesHigher only · separate only
Answer: C Less radiation emitted from the Earth into space
The Earth’s temperature depends on the balance between radiation absorbed and radiation emitted, and on how much sunlight is reflected back into space. Greenhouse gases absorb some of the infrared the Earth emits and re-emit it, so less escapes and the Earth stays warmer.
Checked against AQA GCSE Physics 8463 specification, 4.6.3 Black body radiation (physics only)
27 / Light and electromagnetic wavesBoth tiers
Answer: C Towards the normal
A ray that meets a glass block at an angle bends towards the normal as it goes in, and away from the normal as it comes back out into air. A ray that travels along the normal goes straight through without changing direction.
Checked against AQA GCSE Physics 8463 specification, 4.6.2.2 Properties of electromagnetic waves 1
02 / Longer answersMarked by levels
Write your answer first, on paper. Then open it and tick off the points you made. How 6-mark questions are marked.
6 marks / What sets the Earth’s temperatureHigher only · separate only
The Earth absorbs radiation from the Sun, mostly visible light and infrared, and it also emits radiation, mainly infrared, into space. If the Earth absorbs radiation at the same rate as it emits it, its temperature stays constant. If it absorbs radiation faster than it emits it, its temperature rises, and if it emits radiation faster than it absorbs it, its temperature falls. A hotter object emits radiation at a greater rate, so as the Earth warms it emits more, until the rates balance again at a new, higher temperature. Several factors affect this balance. Clouds, ice and snow reflect some of the Sun’s radiation straight back into space, so it is never absorbed, and less ice means more absorption. Greenhouse gases in the atmosphere, such as carbon dioxide, methane and water vapour, absorb some of the infrared emitted by the Earth’s surface and emit it again in all directions, some of it back towards the surface. If there are more greenhouse gases, less radiation escapes to space, so the Earth absorbs more than it emits and warms until a new balance is reached at a higher temperature.
Saying greenhouse gases form a layer that “traps heat” is too vague. Talk about rates: absorbing radiation faster than emitting it makes the temperature rise, and a constant temperature means the two rates are equal.
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