A microscope is arranged to observe a mark on a piece of paper clearly. Now if a cube of refractive index 1.5 and thickness 3 cm is placed on this mark, then now what should be the displacement given to microscope to observe the mark clearly again ?

Options

A. 4.5 cm downward
B. 1 cm downward
C. 2 cm upward
D. 1 cm upward

Answer

A, C, D

Explanation

In first case, microscope is focussed at P.
In second case, it is focussed at P..
Now, apparent depth,
Real depth of P - Apparent depth of P
`=3-(3)/(1.5)` `(because mu=("real depth")/("apparent depta")`
=3-2 `(therefore`Apparent depth =`("real depth")/(mu))`
=1 cm