An endoscope is employed by a physician to view the internal parts of a body organ. It is based on the principle of

$A$ light ray from air is incident (as shown in the figure) on the lateral surface of a glass fiber (refractive index $\mu = 1.5$) at an angle of incidence of $60^o$, such that it undergoes total internal reflection. How much time would it take for the light to traverse the straight fiber of length $L = 1 \ km$ (in $\mu s$)?

The radius of the light circle observed by a fish at a depth of $12 \ m$ is (refractive index of water $\mu = 4/3$):

White light is incident on the interface of glass and air as shown in the figure. If only green light undergoes total internal reflection,then the rays in the air are:

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

$A$ glass prism of refractive index $1.5$ is immersed in water (refractive index $\frac{4}{3}$) as shown in the figure. $A$ light beam incident normally on the face $AB$ is totally internally reflected at the face $AC$ to reach the face $BC$,if: