question_answer

A microscope is focussed on a dot at the bottom of a beaker. Some oil is poured into the beaker to a height of \[y\] cm and it is 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 \[y\].           

Answer:

                Real depth \[=\text{y cm}\] Apparent depth\[~=y\text{ }-\text{ }x\text{cm}\] Refractive index of oil, \[\text{ }\!\!\mu\!\!\text{  =}\frac{\text{Real depth}}{\text{Apparent depth}}\text{=}\frac{y}{y-x}\]