Question

A spherical mirror and a thin spherical lens have each a focal length of $-15$ cm. The mirror and lens are likely to be :

• A. both concave
• B. both Convex
• C. the mirror is concave and lens is convex
• D. the mirror is convex but lens is concave

Answer 1

The correct option is A both concave

Negative focal length is a characteristic of concave mirror and concave lens. Hence, both mirror and the lens are concave.