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

The plane containing the incident ray and normal is called :

1. plane of reflection
2. normal plane
3. plane of incidence
4. none of the above

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°