The focal length of a convex lens of glass `(mu = 1.5)` in air is 30 cm. Find its focal length when the lens is placed in water `(mu = 4//3)`.

The focal length of a bi-convex glass (mu_g = 1.5) in air is 20 cm. Find its focal lengths in water (mu_w = 1.35) and in carbon di-suphide (mu_(cs) = 1.65).

The focal length of a biconvex glass (mu_g = 1.5) lens in air (mu_alpha = 1) is + 20 cm . Then the focal length of this glass lens in water (mu_omega = 1.33) is

The focal length of a concavo - convex lens of radii of curvature 5 cm and 10 cm is 20 cm.What will be its focal length in water (mu=4//3) ?

The foal length of a glass convex lens in air is 15 cm.Calculate its focal lenth,when is is totally immersed in wate.Given a^mu_w=4//3 and a^mu_g=1.5 .

Focal length of a glass lens in air is 2 cm. Its focal length when immersed in water would be:

A convex glass Iens (mug = 1.5 ) has a focal length 8 cm when place in air. The focal length of the lens when placed in water (mu_w = 4/3) is—

The focal length of the lens of refractive index (mu = 1.5) in air is 10 cm. If air is replaced by water of mu = (4)/(3) , its focal length is