An object P is focussed by a microscope M. A glass slab of thickness 2'1 cm is introduced between P and M. If the refractive index of the slab is P5, by what distance should the microscope be shifted to focus the object again ?

A tank is filled with water to a height of 15.5 cm . The apparent depth of a needle lying at the bottom of the tank is measured by a microscope to be 8.5 cm . If water is replaced by a liquid of refractive index 1.94 up to the same height by what distance would the microscope have to be moved to focus on the needle again ?

A glass slab (mu=1.5) of thickness 6 cm is placed over a paper. What is the shift in the letters?

A small ink dot on a paper is viewed through a glass slab of thickness 10 cm , and refractive index 1.5 . By what distance would the dot appear to be raised ?

A microscope is focused on a mark on a piece of paper and then a slab of glass of thickness 3cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again ?

An object is seen through a glass slab of thickness 36 cm and refractive index 3//2. The observer, and the slab are dipped in water (mu=4//3). The shift produced in the position of the object is

If t is the real thickness mu is refractive index of a glass slab then the shift of the image with refernce to the object is given by

The time taken by a ray of light to travel through a glass slab of thickness 2 cm and refractive index 1.5 will be

Object O is placed in front of a plane mirror M. A glass slab S having thickness t = 3 cm and refractive index mu = 1.8 is placed between the object and the mirror. The refracting faces of the slab are parallel to the mirror surface. The object is made to move with a velocity of u = 2 m//s perpendicular to the mirror surface. Find the speed of the image formed after (a) refraction from the slab followed by reflection from the mirror. (b) refraction from the slab followed by reflection from the mirror followed by the refraction from the slab.

A convex lens of focal length f_(1) is placed in front of a luminous point object. The separation between the object and the lens is 3f_(1) . A glass slab of thikness t is placed between the object and the lens. A real image of the object is formed at the shortest possible distance from the object. a. Find the refractive index of the slab. b. If a concave lens of very large focal length f_(2) is placed in contact with the convex lens, find the shifting of the image.