(a(i))[1]
State which type of electromagnetic radiation, apart from visible light, is used in glass optical fibres.
(a(ii))[2]
Give two reasons why these two kinds of electromagnetic radiation are selected for high-speed broadband in glass optical fibres.
(b(i))[2]
Calculate the refractive index for the glass.
(b(ii))[2]
On Fig. 5.1, draw a light ray in the fibre so that it undergoes total internal reflection.