Question

Two objects `A` and `B` when placed in turn in front of a concave mirror of radius of curvature `15cm`, give images of equal size. If `A` is three times the size of `B` and is placed `30cm` from the mirror, the distance of `B` from the mirror is
A. `20cm`
B. `15cm`
C. `12.5cm`
D. `9.5cm`

Answer 1

Correct Answer - B
`(M_(A))/(M_(B))=(1)/(3)=(f-u_(B))/(f)xx(f)/(f-u_(A))`