A ray of light strikes a glass slab of thickness t.
(i) Prove that it emerges on the opposite face, parallel to the initial ray.
(ii) (ii) Prove that the value of deflection of beam which passed through the plate is :
`t sini_(1)[1-sqrt(((1-sin^(2)i_(1))/(._(a)mu_(g)^(2)-sin^(1)i_(1))))]`
(iii) Prove that for a small angle of incidence `i_(1)`, the internal shift x is given by
`x=t i_(1)(1-(1)/(._(a)mu_(g)))`
where `._(a)mu_(g)` is the refractive index of glass with respect to air.