Ray optics Questions

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

A bird is flying 3 m above the surface of water. If the bird is diving vertically down with speed = 6 m/s, his apparent velocity as seen by a stationary fish underwater is (μwater = 4/3)

A point object O and a mirror M move with velocities of 3 cm s−1 and 4 cm s−1 respectively as shown in the figure. OO′ is the normal to the mirror. The speed of the image will be -

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

The refractive index of prism for a monochromatic light is √3 and its refracting angle is 60°. For minimum deviation angle of incidence should be

Critical angle of incidence for a pair of optical media is 45°. The refractive indices of first and second media are in the ratio:

An object is placed at a distance of 10 cm from a convex lens of power 5D. Find the position of the image :

A mirror is used to produce an image with magnification of . If the distance between object and its image is 40 cm, then the focal length of the mirror is ______.

A rectangular glass slab of thickness 12 cm has rear face silvered. An object is placed 15 cm in front. Final image appears 19 cm behind silvered face. Find refractive index.

A plano-convex lens has a central thickness of 2 mm and an aperture diameter of 8 cm. If the speed of light within the lens material is 2.4 × 108 ms−1, what is the approximate focal length of the lens?

A convex lens of focal length 20 cm is in contact with a concave lens of focal length 40 cm. The power of the combination is