Question

2. Define the following for spherical linses
(i) Focus
(ii) Focal length
(iii) Radius
of
curvature
(iv) Principal asis​

Answer 1

Answer:

(i) Optical center is defined as the point on the lens which is on the principal axis and the light ray doesn't deflect when passes through it.

(ii) Centre of curvature is defined as the center of the surface of sphere of which the lens is a part. Since, a lens has two surfaces, so the lens has two centers of curvatures.

(iii) Principal axis is defined as the straight lines passing through center of curvature.

(iv)Aperture is defined as the diameter of the boundary of the circular lens.