At angle of incidence equal to the critical angle, the angle of refraction is:

1. 0°
2. 30°
3. 90°
4. 180°

The correct relation between critical angle and refractive index of a medium is:

1. cos C = $\dfrac {1}{ {$aμg}}
2. tan C = $\dfrac {1}{ {$aμg}}
3. sin C = $\dfrac {1}{ {$aμg}}
4. sin C = ${}_a{\mu }_g$aμg

The condition required for total internal reflection to take place is:

1. light ray passes from a rarer to denser medium
2. light ray passes from a denser to rarer medium
3. angle of incidence is less than critical angle
4. none of the above

A total reflecting prism is:

1. right-angled prism
2. equilateral prism
3. right-angled isosceles prism
4. all of the above