Question

A light ray passing through the ______ of the lens will not undergo any deviation.

Options

• focus

• centre of curvature

• optical centre

• principal axis

Answer 1

A light ray passing through the optical centre of the lens will not undergo any deviation.

Explanation:

A light ray passing through the optical centre strikes the central part of the lens where both spherical surfaces are practically parallel to each other (like a thin glass slab). As a result, the lateral displacement is negligible for a thin lens, and the ray passes completely straight without any net bending or deviation.