A microscope is focussed on a dot on the bottom of the beaker. Some oil is poured into the beaker to a height of `y cm` and it found necessary to raise the microscope through a vertical distance of `x cm` to bring the dot again into focus. Express refractive index of oil in terms of `x and y`.

A mark at the bottom of a bekar is focussed by a microscope .When water is poured in the beaker up to a height of 16 cm,the microscope has to be raised through a distance of 4 cm in order to bring the mark to focus again .Calculate the refractive index of water.

A travelling microscope is focussed on to a scratch on the bottom of a beaker. Water of refractive index (4)/(3) is poured in it. Then the microscope is to be lifted through 2 cm focus it again. Find the depth of water in the beaker.

A travelling microscope is focussed on to a scratch on the bottom of a beaker. Water of refractive index (4)/(3) is poured in it. Then the microscope is to be lifted through 2 cm focus it again. Find the depth of water in the beaker.

A vertical microscope is focussed on a point at the bottom of an empty tank. Water ( mu = 4//3 ) is then poured into the tank. The height of the water column is 4cm. Another lighter liquid, which does not mix with water and which has refractive index 3/2 is then poured over the water.The height of liquid column is 2cm. What is the vertical distance through which the microscope must be moved to bring the object in focus again ?