Question

An object is placed at a distance of `36 cm` from a convex mirror. A plane mirror is placed inbetween so that the two virtual images so formed coincide. If the plane mirror is at a distance of `24 cm` from the object, find the radius of curvature of convex mirror.

Answer 1

Correct Answer - `36 cm`
Distance of image from plane mirror `=` distance of object from plane mirror. Therefore, for convex mirror, `u = - 36 cm` and
`v = + (24 + 24 - 36) cm = +12 cm`.
From `(1)/(f) = (1)/(v) + (1)/(u) = (1)/(12) + (1)/(- 36) = (1)/(18)`
`f = 18 cm`
`R = 2 f = 2 xx 18 cm = 36 cm`