Multiple choice questions

Which of the following is Snell's law?

The refractive index of glass with respect to air is $2$. Then the critical angle of glass-air interface is _____.

Total internal reflection takes place when the light ray travels from _____

If the angle of incidence is equal to critical angle, then the angle of refraction is 

Mirage is a best example for the phenomenon of 

Refractive indices of Ice, Benzene, Ruby and Kerosene are $1.31$, $1.50$, $1.71$ and $1.44$ respectively. In which of the above media, light travels slowly?

The relative refractive index of water with respect to air is $\frac{4}{3}$. Then relative refractive index of air with respect to water is

In an experiment to trace the path of ray through a glass slab, Shiva traced as shown in the figure. The teacher asked identify the emergent ray. Which of the following would Shiva identify?