Question

In an experiment to study the refraction of light through a rectangular glass slab, a student measured the angle of incidence, angle of refraction and the angle of emergence. The student lost the reading of angle of incidence but noted the readings of angle of refraction to be 35° and angle of emergence to be 65°. The angle of incidence is likely to be:
(1) 45°
(2) 55°
(3) 35°
(4) 65°

Answer 1

When a light ray refracts through a rectangular glass slab, the angle of incidence and the angle of emergence are always equal. That's why, the angle of incidence will be 65°, equal to the given angle of emergence.

Hence, the correct answer is option 4.