A convex lens- of focal length 30 cm- a concave lens of focal length 120 cm- and a plane mirror are arranged as shown- For an object kept a distance of 60 cm from the convex lens- the final image- formed by the combination- is a real image- a distance of -60 cm from the convex lens60 cm from the concave lens70 cm from the convex lens70 cm from the concave lens

Question

Toppr Admin · Accepted Answer

Location of image formation after first refraction from the lens,

$\frac{1}{v} + \frac{1}{60} = \frac{1}{30}$ .

This gives $v = 60 c m$

Next refraction from concave lens,

$\frac{1}{v_{2}} - \frac{1}{40} = - \frac{1}{120}$

Hence $v_{2} = 60 c m$

Since this will be formed behind the mirror, this will be final image.

It is at a distance of $60 c m$ from the concave lens.

Location of image formation after first refraction from the lens,1v+160=130.This gives v=60cmNext refraction from concave lens,1v2−140=−1120Hence v2=60cmSince this will be formed behind the mirror, this will be final image.It is at a distance of 60cm from the concave lens.