A bird is flying 3 m above the surface of water. If the bird is diving vertically down with speed =

A rectangular glass slab of thickness 12 cm has rear face silvered. An object is placed 15 cm in fro

If M.P. of Gallian telescope is 9 & tube length is 80 cm, then fo & fe will be respectively.

A point object O and a mirror M move with velocities of 3 cm s−1 and 4 cm s−1 respectively as shown

Nature of image of a real object formed by concave lens is

Critical angle of incidence for a pair of optical media is 45°. The refractive indices of first and