(a) Draw a ray diagram to explain the term angle of deviation.
(b) Why do the component colours of incident white light split into a spectrum while passing through a glass prism, explain.
(a) Angle of deviation is the angle between extended incident ray and extendent emergent ray through a prism.
PQ = Incident Ray, RS = Emergent Ray
∠D = Angle of Deviation .
(b) The incident white light splits into a seven coloured spectrum as speed of different coloured light waves is different when these pass through the prism.