The radii of curvature fo a lens are `+20cm` and `+30cm` . The material of lens has refractive index `mu=(3)//(2)`. Find fcal length of lens in air.

The radii of curvature of a lens are +20cm and +30cm .The material of the lens has a refractive index 1.6 .Then focal length of the lens (in cm) if it is placed in water of refractive index mu =(4)/(3) is

The radii of curvature of a lens are + 20 cm and + 30 cm. The material of the lens has a refracting index 1-6. Find the focal length of the lens (a) if it is placed in air, and (b) if it is placed in water (mu = 1.33).

The radii of curvature of a lens are + 20 cm and + 30 cm. The material of the lens has a refracting index 1-6. Find the focal length of the lens (a) if it is placed in air, and (b) if it is placed in water (mu = 1.33).

The radii of curvature of a lens are + 20 cm and + 30 cm. The material of the lens has a refracting index 1-6. Find the focal length of the lens (a) if it is placed in air, and (b) if it is placed in water (mu = 1.33).

A thin concavo-convex lens has two surfaces of radii of curvature R and 2R. The material of the lens has a refractive index n. When kept in air, the focal length of the lens.

A thin concavo-convex lens has two surfaces of radii of curvature R and 2R. The material of the lens has a refractive index p. When kept in air, the focal length of the lens

The radius of curvature of each face of biconcave lens, made of glass of refractive index 1.5 is 30 cm. Calculate the focal length of the lens in air.

The radii of curvature of the two surfaces of a lens are 20cm and 30 cm and the refractive index of the material of the lens is 1.5 . If the lens is concave - convex, then the focal length of lens is