The radii of curvature of a convex lens are 15 cm and 30 cm respectively. The refractive index of its material is 1 c...

The radii of curvature of the two surface of a lens are 20 cm 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 the lens is :

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 ?

The radii of curvature of the faces of a double convex lens are 10 cm and 20. The refractive index of the glass is 1.5. What is the power of this lens (in units of dioptre)?

A concave lens has radioi of curvatures of 20 cm and 30 cm respectively. If the refrative index of the material of lens is 1.6 it focal length is given by

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

The radii of curvature of the two surfaces of a lens are 20 cm 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 the lens is

The radii of curvatures of a double convex lens are 15 cm and 30 cm, and its refractive index is 1.5. Then its focal length is -

The radii of curvature of the two surface of a double convex glass lens are 10 cm and 20 cm respectively. If the refractive index of glass in 1.5, then its focal length will be