Question
An observer can see through a pin–hole the top end of a thin rod of height h, placed as shown in the figure. The beaker height is 3h and its radius h. When the beaker is filled with a liquid up to a height 2h, he can see the lower end of the rod. Then the refractive index of the liquid is
 5/2


 3/2
The correct answer is:
The line of sight of the observer remains constant, making an angle of 45° with the normal.
=
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