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Question:

A ray of light is incident at an angle of 60° on one face of a prism of angle 30°. The emergent ray of light makes an angle of 30° with the incident ray. The angle made by the emergent ray with the second face of the prism will be:

0°

30°

90°

45°

Solution:

The correct option is B
90°
Here,
i₁=60°
A=30°
δ=30°
Since, δ=i₁+i₂−A
30=60°+i₂−30
∴ i₂=0
So from the surface, it will make 90°.