A ray of light meets a plane mirror at an angle of incidence 15°. What will be the deviation of the ray after reflection?

Question

Question

This question was previously asked in

ALP CBT 2 Physics and Maths Previous Paper 1 (Held On: 21 Jan 2019 Shift 1)

Answer 1

CONCEPT

Reflection: The phenomena in which a light ray is sent back into the same medium from which it is coming, on interaction with boundary, is called reflection.
Laws of reflection:

The angle of incidence (θi ) = Angle of reflection (θr )
The incident ray, the reflected ray, and the normal to the surface of incidence always lies in the same plane.

F1 J.K 12.6.20 Pallavi D2

The angle of minimum deviation is defined as the smallest angle through which light is bent by a prism.
The relationship between the angle of incidence, angle of emergence and angle of minimum deviation is given by

⇒ δ = 180° - (i +r)

CALCULATION:

Given - Angle of incidence (i) = 15° and Angle of reflection (r) = 15°

⇒ δ = 180° - (i + r)

⇒ δ = 180°- (15° + 15°) = 180° - 30° = 150°