Question

A microscope is focused on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again:-
A. 1 cm upward
B. 4.5 cm downward
C. 1 cm downward
D. 2 cm upward

Answer 1

Correct Answer - A
Shifting in microscope=upward shifting in mark
`=t(1-1/mu)=3(1-(1)/1.5)=1cm`