Q22 of 45 Page 302

Light which is incident on a flat surface makes an angle of 150 with the surface.


i) What is the angle of incidence?


ii) What is the angle of reflection?


iii) Find the angle of deviation.


i) The angle of incidence (i) is (90o-15o) = 75o



ii) From the law of reflection,


The angle of incidence (i) = the angle of reflection (r)


So, the angle of reflection (r) =75o



iii) The angle of deviation (A) is the angle by which the light ray has been deflected due to reflection.


The angle of deviation (A) = 180o- (i+r)


= 180o – (75o + 75o)


= 180o – 150o


= 30o



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