question_answer

Consider the situation shown in figure. Water \[\left( {{\mu }_{w}}=\frac{4}{3} \right)\] is filled in a breaker upto a height of 10 cm. A plane mirror fixed at a height of 5 cm from the surface of water. Distance of image from the mirror after reflection from it of an object O at the bottom of the beaker is

A)            15 cm

B)            12.5 cm

C)            7.5 cm

D)            10 cm

Correct Answer: B

Solution :

                   From figure it is clear that object appears to be raised by \[\frac{10}{4}cm\,\left( 2.5\,cm \right)\] Hence distance between mirror and \[O'=5+7.5=12.5\,cm\] So final image will be formed at 12.5 cm behind the plane mirror.