Question

A wide slab consisting of two media of refractive indices $n_{1}$ and $n_{2}$ is placed in air as shown in the 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 statement(s) is(are) correct?

• 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 $n _{2}< n _{1}$
• C. The light ray is finally reflected back into the medium of refractive index $n_{1}$ if $n_{2}>n_{1}$
• D. The light ray is reflected back into the medium of refractive index $n_{1}$ if $n_{2}=1$

Answer 1

Answer: (B), (C), (D)

The ray diagram for the following conditions are


The light finally must reflected back in medium of refractive index $n_1$ for all values of $n_2$.