The angle of incidence for a ray of light at a
refracting surface of a prism is 45° . The angle of
prism is 60°. If the ray suffers minimum deviation
through the prism, the angle of minimum deviation
and refractive index of the material of the prism
respectively, are :
(1) 45°, ``\frac {1}{\sqrt 2}``
(2) 30°, ``\sqrt 2``
(3) 45°, ``\sqrt 2``
(4) 30°,``\frac {1}{\sqrt 2}``