Optics Question 973
Question: A ray of light travelling in a transparent medium falls on a surface separating the medium from air at an angle of incidence of 45°. The ray undergoes total internal reflection. If n is the refractive index of the medium with respect to air, select the possible value (s) of n from the following
[IIT-JEE 1998]
Options:
A) 1.3
B) 1.4
C) 1.5
D) 1.6
Show Answer
Answer:
Correct Answer: D
Solution:
For TIR i > C
Therefore sin i > sin C
Therefore $ \sin 45{}^\circ >\frac{1}{n} $
Therefore $ n>\sqrt{2} $
Therefore n > 1.4
