Question

A ray of light is incident on a plane mirror at an angle of incidence of 15°. The deviation in the ray produced by the mirror is:

• A. 30°
• B. 60°
• C. 120°
• D. 150°

Answer 1

The Correct Option is A

Step 1: Understanding the relationship between the angle of incidence and the deviation produced by the mirror:
When a ray of light strikes a plane mirror, the angle of incidence is equal to the angle of reflection, according to the law of reflection. The deviation produced by the mirror is the difference between the angle of the incident ray and the reflected ray.

Step 2: Formula for deviation in a plane mirror:
The total deviation \( \delta \) produced by a plane mirror can be calculated using the formula: \[ \delta = 2 \times \text{angle of incidence} \] This is because the angle between the incident ray and the reflected ray is twice the angle of incidence.

Step 3: Applying the given value:
Given that the angle of incidence is 15°, we can calculate the deviation as follows: \[ \delta = 2 \times 15° = 30° \] Thus, the deviation produced by the mirror is 30°.

Step 4: Conclusion:
The deviation in the ray produced by the plane mirror is 30°.