If the space between the lenses in the lens combination shown were filled with water, what should happen to the focal length and power of the lens combination ?

Write expression for the focal length and power of a lens 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?

Focal length of combination of two thin lenses is 1 m. Calculate the power of one lens if the focal length of other lens is 30 cm.

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 ?

An eye specialist prescribes spectacles having combination of convex lens of focal length 40cm in contact with a concave lens of focal length 25cm. The power of this lens combination in diopters is

An eye specialist prescribes spectacles having combination of convex lens of focal length 40cm in contact with a concave lens of focal length 25cm. The power of this lens combination in diopters is