Which of the following is not due to total internal reflection?

Light travels from an optically denser medium $A$ into the optically rarer medium $B$ with speeds $1.8 \times 10^{8} \ m/s$ and $2.7 \times 10^{8} \ m/s$ respectively. The critical angle between them is ($\mu_{A}$ and $\mu_{B}$ are the refractive indices of media $A$ and $B$ respectively).

$A$ ray of light is incident at an angle $i$ from a denser to a rarer medium. The reflected and the refracted rays are mutually perpendicular. The angle of reflection is $r$ and the angle of refraction is $r'$. Then the critical angle $C$ will be:

The critical angle of light passing from glass to air is minimum for which color of light?

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 travelling in water is incident on its surface open to air. The angle of incidence is $\theta$,which is less than the critical angle. Then there will be