Question

A ray of light strikes a glass slab at 90∘. The angle of incidence is:

विकल्प

• 90°

• zero

• less than 90°, but not zero

• none of these

Answer 1

Zero

Explanation:

The ray strikes the slab at right angles to its surface, so it travels along the normal. The angle of incidence, measured from the normal, is zero.