a) Define i) principal focus of a concave mirror
ii) focal length of a concave mirror
b) Draw diagram to represent the action of a concave mirror on a beam of parallel light rays. Mark on this diagram principal axis, focus F, centre of curvature C, pole P, and the focal length f of the concave mirror.

Vinay

3 years ago

I A concave mirror’s primary focus is the place on the principal axis where all of the light rays converge after reflection.

ii) Focal length of a concave mirror: The focal length of a concave mirror is the distance between the pole and the main axis.