A microscope is focussed on a mark on a piece of paper and

Last updated: 6/8/2023

A microscope is focussed 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 again in focus 1 1 cm downward upward 2 1 cm upward 4 45 unward