Question

1. A ray of light that strikes a plane mirror PQ at an angle of incidence of 30°, is reflected from the plane mirror then strikes a second plane mirror QR placed at right angle to the first mirror.The angle of reflection at the second mirror is



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Answer 1

Answer:

Ray AB strikes the mirror PQ at B and gets reflected along BC according to the laws of reflection. The ray BC incident on mirror QR makes an angle of 30o with the mirror. So, the angle of incidence on this mirror is 90o - 30o = 60o. Hence, the angle of reflection is also 60o.