A ray of light travelling in a transparant medium falls on a surface separating the medium from air at an angle of incidence of `45degree`. The ray undergoes total internal reflection. If n is the refractive in index of the medium with respect to air, select the possible value (s) of n from the following:

Options

A. 1.3
B. 1.4
C. 1.5
D. 1.6

Answer

C, D

Explanation

KEY CONCEPT: For total internal reflection to take place:
Angle of incidence `igt` critical angle, `theta_(c)` or `sin45degreegt(1)/(n)` or `(1)/(sqrt2)gt(1)/(n)` or `ngtsqrt2` or `ngt1.414`.
Therefore, possible values of n can be 1.5 or 1.6 in the given options.