Question
(a) What do you understand by the statement, "critical angle for water is $48^{\circ}$ ?
(b) State two conditions for total internal reflection.
(b) State two conditions for total internal reflection.
✓
Answer
(a) Critical angle for water is $48^{\circ}$, means, the rays of light travelling in water, when strike the water-air surface at an angle of $48^{\circ}$, then angle of refraction is $90^{\circ}$.
(b) Two conditions for total internal reflection:
(i) Rays of light must travel from an optically denser medium to an optically rarer modium.
(ii) The angle of incidence in optically denser medium must be greater than the critical angle.
(b) Two conditions for total internal reflection:
(i) Rays of light must travel from an optically denser medium to an optically rarer modium.
(ii) The angle of incidence in optically denser medium must be greater than the critical angle.
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