Optics Question 800
Question: A plane mirror is held at a height h above the bottom of an empty beaker. The beaker is now filled with water up to depth d. The general expression for the distance from a scratch at the bottom of the beaker to its image in terms of h and the depth d of water in the beaker is\
Options:
A) $ 2h-d( \frac{\mu }{\mu -1} ) $
B) $ 2h-\frac{d}{2}( \frac{\mu -1}{\mu } ) $
C) $ 2h-d( \frac{\mu -1}{\mu } ) $
D) $ 2h-d( \frac{2\mu -1}{\mu } ) $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] The distance of bottom of the beaker from mirror $ =h-d( 1-\frac{1}{\mu } ) $
So it will be at a distance $ =h-d( 1-\frac{1}{\mu } ) $ from mirror.
Now distance between bottom of beaker and image $ =h+h-d( 1-\frac{1}{\mu } )=2h-d( \frac{\mu -1}{\mu } ). $