A luminous object is placed at a distance of `30 cm` from the convex lens of focal length `20 cm`. On the other side of the lens, at what distance from the lens a convex mirror of radius of curvature `10 cm` be placed in order to have an upright image of the object coincident with it ?

Options

A. 12 cm
B. 30 cm
C. 50 cm
D. 60 cm

Answer

C

Explanation

u = - 30 cm, f = 20 cm
`(1)/(v) = (1)/(20) - (1)/(30) = + (1)/(60)`
v = 60 cm

`therefore` Separation between lens and mirror
= 60 - 10 = 50 cm.