Find the crtical angle of incidence at the glass `(n_g = 3/2)` and water `(n_w = 4/3)` interface.

A glass prism of refracting angle of 60^@ is set for minimum deviation. The angle of minimum deviation is 30^@ . Find Critical angle at the glass-air interface.

Refractive indices for glass and water are (5//3) and (4//3) respectively. The critical angle at the glass-water interface is

Find the value of (-i)^(4n+3), when n is positive.