If the refractive index of a medium in air is 2.0, what is the critical angle for this medium?
Answer Details
The critical angle is the angle of incidence at which the angle of refraction is 90 degrees, meaning that the refracted ray travels along the surface of the medium rather than entering it. The formula for calculating the critical angle is: critical angle = sin⁻¹ (1/n) where n is the refractive index of the medium. In this question, the refractive index of the medium in air is given as 2.0. Plugging this value into the formula, we get: critical angle = sin⁻¹ (1/2.0) Using a calculator, we can find that sin⁻¹ (1/2.0) is approximately 30 degrees. Therefore, the correct option is 30o.