Uses of the Electromagnetic Spectrum

Fill in the blank:

gamma rays, x-rays, ___________, visible light, infrared, microwaves, radio waves

Which of the listed waves has the highest frequency?

• infrared

• radio waves

• ultraviolet

• x-rays

Which of the listed waves has the longest wavelength?

• infrared

• radio waves

• ultraviolet

• x-rays

Which of these are NOT uses of microwaves?

• optical fibres

• satellite communication

• thermal imaging

• cooking food

Gamma rays are used to sterilise food because they transfer a lot of ______.

Which of these waves can be used for cooking?

• microwaves

• infrared

• visible light

• ultraviolet

Infrared radiation is used in optical fibres. Optical fibres work using

• reflection

• refraction

• scattering

• total internal reflection

Microwaves are used to cook food. The energy from the microwaves are absorbed by _____ molecules in the food.

To detect faked bank notes, ________ light is shone onto the note. That light is absorbed by the ink on the note and re-emitted as visible light.

Explain how x-rays are used to detect broken bones.