Question

The image formed by a convex mirror of focal length 30 cm is a quarter of the object. What is the distance of the object from the mirror?

Answer 1

Correct Answer - `-90cm`
Here, `f = 30 cm, m = 1/4, u = ?`
As `m = -v/u = 1/4, v = -u/4`
As `(1)/(v) + (1)/(u) = (1)/(f), -4/u + 1/u = 1/30` or `-3/u = 1/30` or `u = -90 cm`.