Angular Deviation

Q. Choose the correct option for the given assertion and reason.
Assertion: Two plane mirrors kept at right angle deviate any ray of light by ${180}^{\circ }$ after two successive reflections.
Reason: The above condition is satisfied only for angle of incidence, $i={45}^{\circ }$.

1. Assertion and reason both are correct and reason is the correct explanation of assertion.
2. Assertion and reason both are correct and reason is not a correct explanation of assertion.
3. Assertion is correct, but reason is not correct.
4. Assertion is not correct, but reason is correct.

Q. A ray of light is incident on a plane mirror at an angle ${50}^{\circ }$. The deviation produced by the plane mirror will be

1. ${70}^{\circ }$
2. ${80}^{\circ }$
3. ${120}^{\circ }$
4. ${130}^{\circ }$