A double convex lens is made of glass which has refractive index 1.55 for violet rays and 1.50 for red rays.If the focal length of violet rays is 20cm the focal length of red rays is

A double convex lens is made of glass which has refractive inded 1.55 for voilet rays and 1.50 for red rays. If the focal length for violet rays is 20 cm, the focal length for red rays will be

A double convex lens is made of glass of refractive index 1.5. If its focal length is 30 cm, then radius of curvature of each of its curved surface is

In glass, the speed of violet ray is less than that of red ray.

A double convex thin lens made of glass of refractive index 1.6 has radii of curvature 15 cm each. The focal length of this lens when immersed in a liquid of refractive index 1.63 is :

A double convex lens is made of glass of refractive index 1.55 with both faces of same radius of curvature. Find the radius of curvature required, if focal length is 20 cm .

A double convex lens is made of glass of refractive index 1.55 with both faces of same radius of curvature. Find the radius of curvature required, if focal length is 20 cm .