i. For total internal reflection, the angle of incidence in the denser medium must be greater than critical angle for the given pair of media.
ii. The relative refractive index of air with the water drop is just less than 1 and hence the critical angle is almost equal to 90°.
iii. Angle of incidence i in air, at the water drop, can’t be greater than 90°.
iv. As a result, angle of refraction r in water will always be less than the critical angle.
v. The figures shown indicates that this angle r itself acts as an angle of incidence at any point for one or more internal reflections. But this does not indicate the total internal reflection.
