A tank is filled with water to a height of `12.5 cm` The apparent depth  of a
Channel: Doubtnut
Date: 02/08/2020

A tank is filled with water to a height of `12.5 cm` The apparent depth  of a needle lying at the bottom of the tank is measured by a microscope to be `9.4cm`. What is the refractive index of water ? If water is replaced by a liquid of refractive index `1.63` upto the same height, by what distance would the microscope have to be moved to focus on the needle again ?