The angle which the …………… ray makes with the …………… at the point of incidence is called angle of incidence.

1. reflected, mirror
2. incidence, mirror
3. incidence, normal
4. reflected, normal

Regular reflection occurs when a beam of light falls on a ……………

1. smooth surface
2. polished surface
3. rough surface
4. Both (a) and (b)

According to the law of reflection:

1. $\dfrac{i}{r}$ = Constant

2. $\dfrac{\text {sin i}}{\text {sin r}}$ = Constant

3. i + r = Constant

4. i = r

For a ray incident normally on a plane mirror, the angle of incidence is :

1. 90°
2. 45°
3. 30°
4. 0°