Question

A ray of light is travelling in a glass cube placed in water. Find the critical angle for the glass-water interface. (Refractive index of glass and water are 1.5 and 1.33 respectively).

Answer 1

At critical angel , the refractive angle is equal to ${90}^o$

$n_{glass}\times sinC=n_{water}sin90$ , where C is critical angle

So $1.5sinC=1.33$

$C=si{n}^{-1}0.89$