Light waves travel from an optically rarer medium to an optically denser medium. Its velocity decreases because of a change in . . . . . . .

In the figure shown,the angle made by the light ray with the normal in the medium of refractive index $\sqrt{2}$ is.....$^o$

$A$ light beam is incident on a denser medium whose refractive index is $1.414$ at an angle of incidence $45^o$. Find the ratio of the width of the refracted beam in the medium to the width of the incident beam in air.

When light travels from glass to air,the incident angle is ${\theta _1}$ and the refracted angle is ${\theta _2}$. The true relation is:

$A$ beam of light propagating in medium $A$ with index of refraction $n(A)$ passes across an interface into medium $B$ with index of refraction $n(B)$. The angle of incidence is greater than the angle of refraction; $v(A)$ and $v(B)$ denote the speed of light in $A$ and $B$. Then which of the following is true?

Captain Jack Sparrow tries to observe a fish almost vertically below him in a magical sea of variable refractive index $\mu = y^2 + 1$,where $y$ is the depth below the water surface. Find the apparent depth of the fish below the water level as seen by Captain Jack Sparrow. The actual depth of the fish is $1 \ m$.