Question 398: Ray Optics

Question

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 in focus again ?

Accepted Answer

Apparent depth = $${{real\,depth} \over \mu }$$ = $${3 \over {1.5}}$$ = 2 cm
As image appears to be raised by 1 cm, therefore, microscope must be moved upwards by 1 cm.

Answer

2 cm upward

Answer

1 cm upward

Answer

4.5 cm downward

Answer

1 cm downward

Ray Optics

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 in focus again ?

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