4.5

Question 1

What does the electromagnetic spectrum include?

Answer 1

The electromagnetic spectrum includes radio waves, microwaves, infrared (heat), visible light, UV light, Xrays and gamma waves.

Question 2

True or false: EM waves are transverse.

Answer 2

True: EM waves are transverse i.e the vibrations move at right angles to the energy.

Question 3

True or false: From radio waves to gamma waves, the frequency and energy decreases but the wavelength increases.

Answer 3

False: From radio waves to gamma waves, the frequency and energy increases but the wavelength decreases.

Question 4

What speed do EM waves travel at?

Answer 4

All EM waves travel at 300 000 000 m/s.

Question 5

Why does light behave like a particle and a wave?

Answer 5

Light behaves like a particle and a wave because it is composed of a particle called a ‘photon’ which can
move like a wave.

Question 6

Can light travel through a vacuum?

Answer 6

Light does not need particles and can therefore travel through a vacuum.