Calculate the speed of light in a medium in which critical angle is 45°.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $2.12 × 10^8 m/s$
Refractive index of medium w.r.t. air:
$\mu = \frac{1}{\sin C} = \frac{1}{\sin 45^\circ} = \frac{1}{\frac{1}{\sqrt{2}}} = \sqrt{2}$
Speed of light in medium:
$v = \frac{c}{\mu} = \frac{3 \times 10^8}{\sqrt{2}}$
$v = 2.12 \times 10^8 \, \text{m/s}$