Infrared Radiation

Question 1

What kind of waves are emitted when objects heat up?

Answer 1

Infra red waves

Question 2

What can infrared be used for?

Answer 2

Cooking food, electrical heaters and for infrared cameras

Question 3

How can infrared waves be used to detect things?

Answer 3

This means that detection of infrared waves can be used to detect warm objects and measure temperature from a distance using an infrared camera. The camera will turn the IR radiation into an electrical signal which is displayed on a screen as a picture.

Question 4

What do different colours represent in an image taken with an infrared camera?

Answer 4

different colours represent different temperatures

Question 5

What happens to objects when they absorb infrared radiation?

Answer 5

they heat up

Question 6

Electric heaters and the heating element inside toasters both emit infrared radiation….

Answer 6

along with a small amount of visible light, in order to heat up the air and your toast.

Question 7

How can IR radiation be used to heat things up in food?

Answer 7

Absorbing it causes things to get hotter- it can be used to cook food as the temp of the food increases when it absorbs IR radiation.

Question 8

How can IR radiation be used to heat things up in electrical heaters?

Answer 8

Electric heaters contain a long piece of wire that heats up when a current flows through it. The wire then emits a lot of IR radiation (+ visible light cos it glows). The IR radiation then is absorbed by objects & the air in the room - energy is transferred by the IR waves to the thermal energy stores of the objects causing their temp to increase.