When a ray of light is incident normally with an incident angle (i) on the surface of thin film. What will be the angle of refraction (r)?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 0°
A ray incident normally travels along the normal to the surface, so the angle of incidence is \( i = 0^\circ \). By Snell’s law:
\( \mu_1\sin i = \mu_2\sin r \Rightarrow \sin r = \frac{\mu_1}{\mu_2}\sin 0^\circ = 0 \)
\( r = 0^\circ \)
The ray passes into the film without bending, whatever the refractive indices of the two media.