Question

which of the following is the correct image for the reflection? a b c d e none of the above

Explanation:

Step1: Calculate the angle of incidence

The angle between the incident ray and the surface is \(20^{\circ}\). The angle of incidence \(i\) is \(90^{\circ}- 20^{\circ}=70^{\circ}\) (since the angle of incidence is measured from the normal).

Step2: Use the law of reflection

According to the law of reflection \(i = r\) (angle of incidence equals angle of reflection). The angle between the reflected ray and the surface is \(90^{\circ}-r\). Since \(r = 70^{\circ}\), the angle between the reflected ray and the surface is \(20^{\circ}\), and the reflected ray should be on the opposite side of the normal compared to the incident ray.

Looking at the options:

• Option a: The direction of the ray is wrong (should be on the opposite side of the normal).
• Option b: The angle with the surface is correct (\(20^{\circ}\)), but the ray direction is wrong (should be going away from the surface as a reflected ray).
• Option c: The angle with the surface is \(20^{\circ}\), but the direction is wrong (incident ray comes in, reflected ray goes out in the correct angular relation but direction is wrong in terms of reflection).
• Option d: The angle \(40^{\circ}\) with the surface is incorrect.

Answer:

E. none of the above