Critical Angle — Prelims Questions

Light travels from glass (refractive index $n_g = 1.5$) to air (refractive index $n_a = 1.0$). What is the critical angle for the glass-air interface?

A light ray is incident from water (refractive index $4/3$) to air (refractive index $1$). If the angle of incidence is $50^circ$, what will happen to the light ray?

Which of the following colors of light has the smallest critical angle when traveling from glass to air?

An optical fiber has a core of refractive index $1.6$ and a cladding of refractive index $1.4$. What is the critical angle for the core-cladding interface?

A point source of light is placed at the bottom of a tank filled with water (refractive index $4/3$) to a depth of $h = sqrt{7}$ m. What is the radius of the circular bright patch of light formed on the surface of the water?

If the critical angle for a medium-air interface is $30^circ$, what is the refractive index of the medium?