A wide slab consisting of two media of refractive indices `n_1` and `n_2` is placed in air as shown in figure. A ray of light is incident from medium `n_1` to `n_2` at an angle `theta` where `sin(theta)` is slightly larger than `1/(n_1)`. Take refractive index of air as 1. Which of the following statements is/are correct?

Options

A. The light ray enters air if `n_2 = n_1`
B. The light ray is finally reflected back into the medium of refractive index `n_1` if `n_2 lt n_1`
C. The light ray is finally reflected back into the medium of refractive index `n_1` if `n_2 gt n_1`
D. The light ray is reflected back into the medium of refractive index `n_1` if `n_2 = 1`

Answer

A

Explanation

The question is solved through the Snell's law on Multiple Boundaries:
'n_1*(sin(theta1))' = 'n_2*sin(theta2)' = n_3*sin(theta3)