A concavo-convex lens has refractive index `1.5` and the radii of curvature of its surfaces are `10 cm and 20 cm.` The concave surface is upwords and is filled with oil of refractive index `1.6.` The focal length of the combination will be

A concavo-convex lens is made of glass of refractive index 1.5. The radii of curvature of its two surfaces are 30 cm and 50 cm. Its focal length when placed in a liquid of refractive index 1.4 is

A concavo-convex lens is made of glass of refractive index 1.5. The radii of curvature of its two surfaces are 30 cm and 50 cm. Its focal length when placed in a liquid of refractive index 1.4 is

A plano-convex lens has refractive index 1.6 and radius of curvature 60 cm. What is the focal length of the lens?

A plano-convex lens has refractive index 1.6 and radius of curvature 60 cm. What is the focal length of the lens?

If the radii of curvature of the two surfaces of a concave lens are 10 cm and 20 cm respectively and the refractive index is 1.5. What is its focal length ?

A plano-convex lens is made of glass of refractive index 1.6. the radius of curvature of its curved surface is 30 cm. What is the focal length of the lens ?

The concave surface of a thin concavo -convex lens of glass of refractive index 1.5 has a radius of curvature of 20cm .The concave surface has a radius of curvature of 60cm .The covnex side is silvered and placed on a horizontal surface as shown in the figure. The focal length of the combibnation has the magnitude.