Question

A ray of light travelling in a transparent medium falls on a surface separating the medium from air at an angle of incidence 45${}^{\circ }$. The ray undergoes total internal reflection. The possible value of refractive index of the medium with respect to air is

• A. 1.245
• B. 1.324
• C. 1.414
• D. 1.524

Answer 1

Answer: (C)

${\mu }_{medium}\times \sin {45}^{\circ }={\mu }_{air}$

$\frac{{\mu }_{medium}}{{\mu }_{air}}=\frac{1}{\sin {45}^{\circ }}=\sqrt{2}=1.414$