An object is placed `12 cm` to the left of a diverging lens of focal length `-6.0 cm.` A converging lens with a focal length of `12.0 cm` is placed at a distance d to the right of the diverging lens. Find the distance d that corresponds to a final image at infinity.

Answer

A, C, D

Explanation

Applying lens formula `1/v-1/u=1/f` twice we have,
`1/v_1-1/(-12)=1/-6`………(i)
`1/oo-1/(v_1-d)=1/12`………(ii)
Solving Eqs. `(i)` and `(ii)`, we have
`v_1=-4cm` and `d=8cm`