The critical angle of light going from medium $x$ to medium $y$ is $\theta$. The speed of light in medium $x$ is $v$. The speed of light in medium $y$ is:

For a light ray to undergo total internal reflection ($i =$ angle of incidence,$i_c =$ critical angle):

One of the necessary conditions for total internal reflection to take place is ($i =$ angle of incidence,$i_{c} =$ critical angle).

$A$ small bulb is placed at the bottom of a tank containing water to a depth of $\sqrt{7} \; m$. The refractive index of water is $\frac{4}{3}$. The area of the surface of water through which light from the bulb can emerge out is $x \,\pi \; m^{2}$. The value of $x$ is ...............

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

Let the refractive index of a denser medium with respect to a rarer medium be $n_{12}$ and its critical angle be $\theta_C$. At an angle of incidence $A$ when light is travelling from a denser medium to a rarer medium,a part of the light is reflected and the rest is refracted,and the angle between the reflected and refracted rays is $90^o$. Angle $A$ is given by