(a) Describe briefly, with the help of suitable diagram, how the transverse nature of light can be demonstrated by the phenomenon of polarisation,
(b) When unpolarised light passes from air to a transparent medium, under what condition does the reflected light get polarised ?
When a polaroid P1is rotated in the path of an unpolarised light, there is no change in transmitted intensity.
The light transmitted through polaroid P1 is made to pass through polaroid P2.
On rotating polaroid P2 in path of light transmitted from P1 we notice the change in intensity of transmitted light. This shows that light transmitted from P1 is polarised. Since light can be polarised, it has transverse nature.
(b) Whenever the reflected and refracted rays are perpendicular to each other.