(a(i))[1]
In the table, put a tick in the box beside the approximate value for the speed of light in air.
(a(ii))[2]
Calculate the wavelength of the light in air.
(b(i).1)[1]
Explain why refractive index has no unit.
(b(i).2)[2]
Calculate the speed at which light travels in the glass.
(b(ii))[3]
Describe one way optical fibres are used in communication technology.