Assertion A ray of light incident along the normal to the plane mirror retraces its path after reflection from the mirror. Reason A ray of light along the normal has angle of incidence as π / 2 and hence, it retraces its own path after reflection from mirror.

Question

Assertion A ray of light incident along the normal to the plane mirror retraces its path after reflection from the mirror. Reason A ray of light along the normal has angle of incidence as π / 2 and hence, it retraces its own path after reflection from mirror. (A) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion. (B) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion. (C) Assertion is correct but Reason is incorrect. (D) Assertion is incorrect but Reason is correct.

Tardigrade Admin · Accepted Answer

Angle of incidence = Angle between incident ray and normal to the mirror =0° <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/f85090bf80209629b702ee78b8a751ca-.png" /> ⇒ Angle of reflection =0° (from laws of reflection) Hence, the reflected ray retraces its path along the normal at an angle 0° with normal.

Q. Assertion A ray of light incident along the normal to the plane mirror retraces its path after reflection from the mirror.
Reason A ray of light along the normal has angle of incidence as $π /2$ and hence, it retraces its own path after reflection from mirror.

Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.

Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.

Assertion is correct but Reason is incorrect.

Assertion is incorrect but Reason is correct.

Angle of incidence $=$ Angle between incident ray and normal to the mirror $= 0^{\circ}$

$\Rightarrow$ Angle of reflection $= 0^{\circ}$ (from laws of reflection)
Hence, the reflected ray retraces its path along the normal at an angle $0^{\circ}$ with normal.

Q. Assertion A ray of light incident along the normal to the plane mirror retraces its path after reflection from the mirror. Reason A ray of light along the normal has angle of incidence as π/2 and hence, it retraces its own path after reflection from mirror.