The wavelengths of given light waves in air and in a medium are $6000 \ Å$ and $4000 \ Å$ respectively. The critical angle is

For total internal reflection to occur, which one of the following is the correct statement? $(i = \text{angle of incidence}, i_{C} = \text{critical angle})$.

$A$ ray of light originates from inside a glass slab and is incident on its inner surface at an angle $\theta$ as shown below. In this experiment,the location $x$ of the spot where the ray hits the screen is recorded. Which of the following correctly shows the plot of variation of $x$ with the angle $\theta$?

Consider the ray diagram for the refraction given below. The maximum value of angle $\theta$ for which the light suffers total internal reflection at the vertical surface is:

$A$ transparent cube of side $d$,made of a material of refractive index $\mu_2$,is immersed in a liquid of refractive index $\mu_1$ (where $\mu_1 < \mu_2$). $A$ ray is incident on the face $AB$ at an angle $\theta$ (as shown in the figure). Total internal reflection takes place at point $E$ on the face $BC$. The angle $\theta$ must satisfy:

Consider a glass prism immersed in a liquid as shown below. The refractive index of glass and liquid is $1.5$ and $1.2$, respectively. $A$ ray of light enters the prism perpendicular to the face $AB$. If the ray is totally internally reflected at the face $AC$, then the largest value of angle $\theta$ is: