Question

a convex lens of focal length 20 cm and a plane mirror are arranged as shown in figure .distance between mirror and lens is 40 cm.if point source S is placed at distance 30 cm from lens then the distance of image formed by mirror from principal axis is​

Answer 1

Answer:

From lens formula,

f

1

=

v

1

−

u

1

⇒

v

1

=

f

1

+

u

1

=

20

1

−

12

1

=

4

1

(

5

1

−

3

1

)

=−

4

1

(

15

2

)

Image distance for convex lens, v=−30cm

Distance of image formed by lens from mirror =40cm

∴ Final image formed behind the mirror =40cm