Question

How to draw a normal to the ray?

Answer 1

Reflection

1. Reflection is a phenomenon of light in which when a light ray hits a surface it deflects its direction and propagates back in a different path.
2. The first law of reflection is that the incident ray, reflected ray, and the normal of the reflection all lie on the same plane.
3. The second law of reflection is that the angle of the incident ray is equal to the angle of the reflected ray from normal.

Reflection through normal

1. Normal is a line drawn perpendicular to the reflecting surface at the same point as the point of incidence.
2. The angle made by the incident ray with the normal is known as the angle of incidence similarly the angle made by the reflected ray with the normal is known as the angle of reflection.
3. Hence, when the incident ray is incident through normal, the incident angle is $0°$.
4. Since the incident angle is equal to the reflected angle, the reflected angle is also $0°$.
5. Therefore, the light will reflect back through the normal itself.