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} $
