A light ray is incidenton a plane glass slab of thickness t at an angle of incidence t as shown in the figure . If mu is the refractive index of glass. Then find time taken by the light ray to travel through the slab.

A light ray is incidenton a plane glass slab of thickness t at an angl

1.	A light ray is incidenton a plane glass slab of thickness t at an angle of incidence t as shown in the figure . If mu is the refractive index of glass. Then find time taken by the light ray to travel through the slab.
Answer» Solution :As shown in the above figure distance travelled by the light ray through the SLAB is d From the figure `cos R=t/d, d= t/ (cos r)` Velocity of light in glass = `(Distance travell ED through the glass)/ (time) ` `C/mu= d/(time), time = (d mu)/c= (t mu )/ (cos r times c) = (mu^2 t)/ ( c sqrt(mu^2- sin^2 i))`