GCSE Questions - Electromagnetic Spectrum

Q6.A laser emits light waves in the visible region of the electromagnetic spectrum.

(a) What type of wave are all electromagnetic waves? [1 mark] Transverse

(b) The light from a laser has a wavelength of 6.5 x 10-7 m.

The speed of light is 3.0 x 108 m/s.

Calculate the frequency of the light from the laser.

(Give your answer to 2 significant figures). [4 marks]

Wavespeed (m/s) = Frequency (Hz) x Wavelength (m)

v = fλ

f = v/λ

f = (3.0 x 108)/(6.5 x 10-7)

f = 4.6 x 1014 Hz ( to 2 sig figs)

(c) What is the approximate range of wavelengths of the electromagnetic spectrum?

Tick () one box. [1 mark]

Tick ()
Range of wavelengths in metres
10-10 to 108
10-8 to 106
10-15 to 104

 

(Total 6 marks)