Question

The reflected ray from a plane mirror is incident on another plane mirror which is placed perpendicular to the first. If the angle of incidence on the first mirror is ${30}^0$, determine the glancing angle of reflection on the second mirror.

• A. ${15}^0$
• B. ${120}^0$
• C. ${60}^0$
• D. ${30}^0$

Answer 1

The correct option is D ${30}^0$

${90}^o-$angle of reflection from second surface is the glancing angle of reflection from the second mirror.

From the image, it can be seen that angle of reflection of second mirror is ${60}^o$

So, glancing angle of reflection of the second mirror $={90}^o-{60}^o={30}^o$

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