Question

Draw a diagram to explain the following terms.
pole of a mirror, principal axis, concave surface, focus, centre of curvature

Answer 1

Pole:
The centre of a mirror is known as its pole (P).

Principal axis:
The straight line passing through the centre of curvature and pole of a mirror is called principal axis.

Concave surface:
A bent-in surface of concave mirror at which reflection of light takes place is called concave surface.

Focus:
Focus (F) is a point in front of a mirror at which all the parallel rays of light converge after getting reflected from the concave mirror.

Centre of curvature:
Centre of curvature (C) is the centre of the hollow sphere of glass of which the mirror is a part.