A ray is incident at an angle of incidence i on one surface of a small angle prism (with the angle of prism A) and emerges normally from the opposite surface. If the refractive index of the material of the prism is then the angle of incidence is nearly equal to:
In Young's double-slit experiment, if the separation between coherent sources is halved and the distance of the screen from the coherent courses is doubled, the fringe width becomes
The Brewsters angle for an interface should be: