A ray of light strikes a plane mirror at an angle of incidence of $30^{\circ }$. What is the angle between the reflected ray and the normal to the mirror?

Step-by-step solution

1. State the law of reflection: the angle of incidence equals the angle of reflection measured with respect to the normal.
2. Given angle of incidence $i=30^{\circ }$, the angle of reflection $r$ is also $30^{\circ }$.
3. The angle between the reflected ray and the normal is the angle of reflection itself, so it is $30^{\circ }$.

Concept tested: Law of reflection

Published 21 August 2026 · How this solution was prepared and checked

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