If a light ray incidents normally an one of the faces of the prism of refractive index 2 and emergent ray just grazes the second face of the prism, then the angle of deviation is

If a light ray incidents normally an one of the faces of the prism of

1.	If a light ray incidents normally an one of the faces of the prism of refractive index 2 and emergent ray just grazes the second face of the prism, then the angle of deviation is
Answer» `0^@` `30^@` `60^@` `90^@` Answer :C