Question

If the angle of incidence is ${50}^{\circ }$, then calculate the angle between the incidence ray and the reflected ray is ?

• A. ${50}^{\circ }$
• B. ${100}^{\circ }$
• C. ${130}^{\circ }$
• D. ${80}^{\circ }$

Answer 1

The correct option is B ${100}^{\circ }$

The angle of incidence, $\angle ANM=i={50}^0$

By law of reflection $i=r$

So, the angle of reflection, $\angle MNB=r=i={50}^0$

Angle between the incident and the reflected ray $=i+r={50}^0+{50}^0={100}^0$.

However, if we were asked the angle between the "direction" of incident ray and reflected ray, then it would be $\angle CNB$

$\angle CNB={180}^o-(i+r)={180}^o-{100}^o={80}^o$