A thin equiconvex lens `(mu=3//2)` of focal length 10cm is cut and separated and a material of refractive index 3 is filled between them. What is the focal length of the combination?

A convex lens of focal length 10.0 cm is placed in contact with a convex lens of 15.0 cm focal length. What is the focal length of the combination ?

Two identical equiconvex lenses of refractive index 3//2 and focal length 16 cm are kept in contact. The space between the lenses is filled with water of refractive index 4//3 . What is the focal length of the combination ?

Two identical equiconvex lenses of refractive index 3/2 and focal length 16cm are kept in contact. The space between the lenses is filled with water of refractive indext 4/3 . What is the focal length of the combination?

A convex lens of focal length 10 cm is placed in contact with a concave lens of focal length 20 cm. What is the nature and focal length of the combination ?

A convax lens of focal length 10.0cm is placed in contact with a convex lens of 15.0cm focal length ,What is the focal length of the combination.

A convex lens of focal length 20 cm is placed in contact with a concave lens of focal length 10 cm. What is the focal length and power of the combination ?

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 20 cm in air is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Now the focal length will be