A concave lens of focal length 12 cm and a convex lens of focal length

1.	A concave lens of focal length 12 cm and a convex lens of focal length 20 cm are kept in contact with each other, (i) Find the focal length of the combination, (ii) What will be the behaviour of the combination?
Answer» (i) f = -30 cm (ii) The combination will behave as a concave lens.

A concave lens of focal length 12 cm and a convex lens of focal length 20 cm are kept in contact with each other, (i) Find the focal length of the combination, (ii) What will be the behaviour of the combination?

Answer»

(i) f = -30 cm

(ii) The combination will behave as a concave lens.