NEET Solved Paper 2016 Question 22

Question: The angle of incidence for a ray of light at a refracting surface of a prism is $ 4{5^{o}}\text{.} $ The angle of prism is $ 6{0^{o}}\text{.} $ If the ray suffers minimum deviation through the prism, the angle of minimum deviation and refractive index of the material of the prism respectively, are :

Options:

A) $ 4{5^{o}}\text{,},\frac{1}{\sqrt{2}} $

B) $ {30^{o}}\text{,},\sqrt{2} $

C) $ {45^{o}}\text{,},\sqrt{2} $

D) $ {30^{o}}\text{,},\frac{1}{\sqrt{2}} $

Show Answer

Answer:

Correct Answer: B

Solution:

  • $ i=45^{0};,A=60^{o};,{\delta_m}=2i,-A=30^{o} $ $ \mu =\frac{\sin ( \frac{A+{\delta_m}}{2} )}{sinA/2}=\frac{\sin 45^{o}}{\sin 30^{o}}=\frac{1}{\sqrt{2}}.\frac{2}{1}=\sqrt{2} $