A convex lens of power `2 D` and a concave lens of focal length
`40cm`are kept in contact, find
(a) Power of combination , (b) Equivalent focal length

A convex lens of focal lenth 30 cm and a concave lens of focal length 60 cm are placed in contact.Find the power of the combination.

A convex lens of focal length 30 cm and a concave lens of focal length 0.6m are placed in contact. Find the power of the combination.

If a convex lens of focal length 10 cm and a concave lens of focal length 50 cm are kept in contact with each other , (i) what will be the focal length of the combination ? (ii) What will be the power of the combination? (iii) What will be the behaviour of the combination ( behaviour as a convex lens / concave lens ) ?

A convex lens of focal length A and a concave lens of focal length B are placed in contact. The focal length of the combination is

A convex lens of focal length A and a concave lens of focal length B are placed in contact. The focal length of the combination is

A convex lens of focal length x and a concave lens of focal length y are placed in contact. The focal length of the combination is

If the convex lens of focal length 10 cm and a concave lens of focal length 50 cm are kept in contact with each other. What will be the focal length of the combination ?

A convex lens of focal length 25 cm and a concave lens of focal length 10 cm are joined together. The power of the combination will be

If 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 be the focal length of the combination ? (ii) What will be the behaviour of the combination ?