Revise Infrared Radiation in GCSE Science Physics

Science Quiz - Physics - Infrared Radiation (AQA) (Questions)

Discover how infrared radiation transfers heat, why dark surfaces warm up fastest, and how greenhouse gases trap energy in Earth’s atmosphere and affect our climate.

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Fascinating Fact:

Greenhouse gases absorb outgoing infrared from Earth and re radiate it, which warms the atmosphere.

In GCSE Science (Physics), you learn how objects absorb and emit infrared radiation. You compare dark and light surfaces, shiny and dull materials, and link infrared behaviour to global warming and insulation.

Key Terms

Infrared radiation: An invisible form of electromagnetic radiation that carries thermal energy away from warm objects.
Absorption: When a material takes in energy from radiation, often causing its temperature to increase.
Emission: When an object gives out energy as radiation, usually because it is warmer than its surroundings.

Frequently Asked Questions (Click to see answers)

What is infrared radiation in GCSE Physics?

Infrared radiation is a type of electromagnetic radiation that transfers energy as heat. All objects emit it, and hotter objects emit more infrared than cooler ones.

Why do dark, matte surfaces heat up faster in sunlight?

Dark, matte surfaces are good absorbers of infrared and visible radiation. They take in more energy and reflect less, so they warm up faster than light, shiny surfaces.

How do greenhouse gases warm Earth’s atmosphere?

Greenhouse gases let most sunlight pass through but interact strongly with infrared radiation. They absorb some of the outgoing infrared and then emit it in all directions, helping keep Earth warmer.

Try These Related Quizzes

Thermal radiation can only travel through which substances?

[ ]	Solids
[ ]	Liquids
[ ]	Gases
[ ]	Transparent and translucent substances

Which one of the following emits the most infrared radiation?

[ ]	1 kg of water at 95^oC
[ ]	1 kg of iron at 68^oC
[ ]	1 kg of your body at 37^oC
[ ]	1 kg of crude oil at 72^oC

Which are the best emitters of thermal radiation?

[ ]	Black, dull surfaces
[ ]	Light coloured dull surfaces
[ ]	Black shiny surfaces
[ ]	Light coloured shiny surfaces

Put the following in order of best to worst reflectors of infrared radiation:

1. Red, dull
2. White, shiny
3. Black, dull
4. Red, shiny

[ ]	1, 3, 4, 2
[ ]	2, 4, 1, 3
[ ]	1, 2, 3, 4
[ ]	4, 1, 3, 2

In sunny countries, houses are often painted white. Why?

[ ]	Painting them white lowers the U-value of the walls
[ ]	White paint does not conduct heat
[ ]	White is a good reflector of thermal radiation
[ ]	The white paint reflects the light into the narrow streets which otherwise would be dark

Why are car radiators often painted matt black?

[ ]	So that splashes of engine oil won't show up
[ ]	To make them more efficient
[ ]	To make the car more attractive to buyers
[ ]	It is a legal requirement

In an electric toaster, what methods of heat transfer cook the bread?

[ ]	Mainly radiation with some conduction
[ ]	Mainly conduction and some radiation
[ ]	Conduction and convection only
[ ]	Mainly convection but conduction has a part to play too

Thermal radiation travels at what speed?

[ ]	Very slowly
[ ]	Instantaneously
[ ]	The speed of sound
[ ]	The speed of light

Which of the following does not use infrared radiation?

[ ]	Security lamps
[ ]	A head torch
[ ]	A remote control for a TV
[ ]	An intruder alarm

10.

The inside container of a vacuum flask is silvered. Why?

[ ]	To reduce heat loss by radiation
[ ]	To completely prevent heat loss by radiation
[ ]	To reduce heat loss by evaporation
[ ]	To reduce heat loss by condensation

Science Quiz - Physics - Infrared Radiation (AQA) (Answers)

Thermal radiation can only travel through which substances?

[ ]	Solids
[ ]	Liquids
[ ]	Gases
[x]	Transparent and translucent substances

It can also travel through vacuums like space. It is very easily absorbed by opaque objects

Which one of the following emits the most infrared radiation?

[x]	1 kg of water at 95^oC
[ ]	1 kg of iron at 68^oC
[ ]	1 kg of your body at 37^oC
[ ]	1 kg of crude oil at 72^oC

The hotter the object, the more infrared it emits

Which are the best emitters of thermal radiation?

[x]	Black, dull surfaces
[ ]	Light coloured dull surfaces
[ ]	Black shiny surfaces
[ ]	Light coloured shiny surfaces

They are also the best absorbers of thermal radiation

Put the following in order of best to worst reflectors of infrared radiation:

1. Red, dull
2. White, shiny
3. Black, dull
4. Red, shiny

[ ]	1, 3, 4, 2
[x]	2, 4, 1, 3
[ ]	1, 2, 3, 4
[ ]	4, 1, 3, 2

Where the colour is the same, shiny surfaces will reflect infrared better than dull ones. Dull surfaces scatter or absorb more of the incoming radiation

In sunny countries, houses are often painted white. Why?

[ ]	Painting them white lowers the U-value of the walls
[ ]	White paint does not conduct heat
[x]	White is a good reflector of thermal radiation
[ ]	The white paint reflects the light into the narrow streets which otherwise would be dark

Infrared radiation from the Sun heats up the outside of buildings. The heat then conducts through the walls and, if the sun shines on them all day, the inside of the buildings would become unbearably hot. Using white paint reflects the infrared radiation, keeping the walls cooler so less heat is conducted to the inside

Why are car radiators often painted matt black?

[ ]	So that splashes of engine oil won't show up
[x]	To make them more efficient
[ ]	To make the car more attractive to buyers
[ ]	It is a legal requirement

The radiator is designed to reduce the temperature of the cooling water circulating round the engine. Painting it black increases the amount of infrared radiation it gives out, making it more efficient

In an electric toaster, what methods of heat transfer cook the bread?

[x]	Mainly radiation with some conduction
[ ]	Mainly conduction and some radiation
[ ]	Conduction and convection only
[ ]	Mainly convection but conduction has a part to play too

Cooking is done using red hot wires. These give out a lot of thermal radiation. This heats the surface of the bread and the heat is conducted into the bread, cooking the inside of the slice. There is a gap between the heating wires and the bread so convection will play little or no part as the hot air rises out of the toaster in a convection current

Thermal radiation travels at what speed?

[ ]	Very slowly
[ ]	Instantaneously
[ ]	The speed of sound
[x]	The speed of light

It is a member of the electromagnetic spectrum