(a) (i) Write Einstein.s photo electric equation.
(ii) if the frequency of the incident radiation is increased from `4xx10^(15)` Hz to `8xx10^(15)` Hz by how much will the stopping potential for a given photosensitive surface go up ?
(b) Laser light of wavelength `630` nmis incident on a pair of slits which are separated by `1.8` mm. If the screen is kept `80` cm away from the two slits. calculate :
(i) fringe separation i.e., fringr width
(ii) distance of `10^("th")` bright fringe from the centre of the interference pattern.

Explanation

(b) According to Huygen, light is longitudinal wave. Polarisation does not support it.