Question

A ray of light strikes a plane mirror at an angle of incidence \(30^\circ\). What is the angle between the incident ray and the reflected ray?

• A. \(30^\circ\)
• B. \(60^\circ\)
• C. \(90^\circ\)
• D. \(120^\circ\)

Hint:

For a plane mirror, the angle between the incident and reflected ray is always \(2i\), where \(i\) is the angle of incidence.

Answer 1

The Correct Option is B

Step 1: Grasp the Law of Reflection The law of reflection dictates that: \[ \text{Angle of incidence } i = \text{Angle of reflection } r \] Provided: \( i = 30^\circ \Rightarrow r = 30^\circ \) Step 2: Determine the Angle Between Incident and Reflected Rays The incident and reflected rays lie on opposing sides of the normal, each forming a \(30^\circ\) angle with it. Consequently, the angle separating them is: \[ \text{Angle between incident and reflected ray} = i + r = 30^\circ + 30^\circ = 60^\circ \] Answer: The correct selection is option (2) \(60^\circ\).