question_answer

A hemispherical glass body of radius 10cm and refractive index 1.5 is silvered on its curved surface. A small air bubble is 6cm below the flat surface inside it along the axis. The position of the image of the air bubble made by the mirror is seen:   JEE Main Online Paper (Held On 10 April 2016)

A) 20 cm below flat surface

B) 30 cm below flat surface                

C) 16 cm below flat surface                

D) 14 cm below flat surface

Correct Answer: A

Solution :

                          \[\frac{1}{V}+\frac{1}{-4}=\frac{1}{-5}\]              \[\frac{1}{V}+\frac{1}{4}-\frac{1}{5}=\frac{5-4}{20}\]              \[V=20\,cm\] 1 acts as object for plane surface \[d'\frac{d}{{{n}_{rel}}}=\frac{30}{1.5}\] \[d'\frac{300}{15}=20\,cm\] 20 cm below plane surface