question_answer

 A ray of light is incident on a plane mirror at an angle of \[60{}^\circ \]. The angle of deviation produced by the minor is

A) \[120{}^\circ \]

B) \[30{}^\circ \]

C) \[60{}^\circ \]

D)        \[90{}^\circ \]

Correct Answer: C

Solution :

Here, angle of incidence,\[i={{60}^{o}}\] \[\therefore \]Angle of deviation                 \[\delta ={{180}^{o}}-(i+r)\]                 \[={{180}^{o}}-2i\]                           \[(\text{As}\,\,i=r)\]                 \[={{180}^{o}}-2\times {{60}^{o}}={{60}^{o}}\]