The electromagnetic spectrum: Waves in matter: Physics: GCSE (9:1)

Electromagnetic (EM) waves

Transverse waves

What EM waves transfer

Energy as radiation from the source of the waves to an absorber

What EM waves travel through

They can travel through a vacuum

Speed of EM waves n a vacuum or air

300,000,000 metres per second (m/s)

Electromagnetic spectrum

A continuous spectrum of electromagnetic waves that are grouped in terms of their wavelength and their frequency

EM spectrum in order of increasing frequency

Radio, microwave, infrared, visible light, ultraviolet, X-rays and gamma rays

EM spectrum in order of increasing wavelength

Gamma rays, X-rays, ultraviolet, visible light, infrared, microwave and radio

Visible light spectrum

Contains all the frequencies that can be detected by the human eye

Uses of radio waves

Communication such as television and radio

Uses of microwaves

Cooking food and for satellite communications

Uses of infrared

Electrical heaters, microwave ovens, and infrared cameras which can detect people in the dark

Uses of visible light

Fibre optic communications

Uses of ultraviolet light

Tanning equipment, energy-efficient lamps

Uses of X-rays

X-ray photos are used to help identify broken bones

Uses of gamma rays

Sterilising food and medical equipment

(higher-tier only)

Producing radio waves

Radio waves can be produced by oscillations from an alternating current in electrical circuits

(higher-tier only)

Absorbing radio waves

Radio waves can themselves produce oscillations and induce an alternating current in an electrical circuit when they are absorbed