Question

State the rules for drawing ray diagrams for spherical mirrors? Support them with ray diagrams.

Answer 1

Rules for drawing ray diagrams for spherical mirrors:

1. An incident ray parallel to the principal axis :

1. In the case of a concave mirror, an incident ray parallel to the principal axis passes through its focus after reflection.
2. In the case of a convex mirror, the incident ray after reflection appears to come from the focus of the mirror.

2. An incident ray passing through the focus :

1. In a concave mirror, an incident ray passing through the focus is reflected parallel to the principal axis.
2. In the case of a convex mirror, the incident ray, which appears to move in the direction of the focus of the mirror, is reflected parallel to the principal axis.

3. An incident ray passing through the centre of curvature :

1. An incident ray passing through the centre of curvature of a concave mirror reflects back along the same path, without any deviation.
2. In the case of a convex mirror, an incident ray that appears to move towards the direction of centre of curvature is reflected back along the same path without any deviation.

4. A ray of light incident at the pole of the mirror :

1. In a concave mirror, a ray of light incident at the pole gets reflected along a path such that the angle of incidence is equal to the angle of reflection.
2. For a convex mirror, a ray of light incident at the pole gets reflected along a path such that the angle of incidence is equal to the angle of reflection.