Question

A converging beam of rays is incident on a diverging lens. Having passed through the lens the rays

Answer 1

Dear student

 

Given,
Image distance, v=15 cm
Object distance, u=15-5=10 cm (It is the distance when lens is removed. i.e object distance)
Now,
Using formula,
1/v-1/u=1/f
or 1/f=1/15 -1/10
or f=-30 cm

 

Answer 2

Given,

Image distance, v=15 cm

Object distance, u=15-5=10 cm (It is the distance when lens is removed. i.e object distance)

Now,

Using formula,

1/v-1/u=1/f

or 1/f=1/15 -1/10

or f=-30 cm