Question

Two plane mirrors are placed at angle between them. If a ray of light incident at
certain angle then the angle of deviation produced by the mirrors together is​

Answer 1

GiveN :-

• Two plane mirrors are placed at angle between them. If a ray of light incident at
• certain angle

To FinD :-

• The angle of deviation produced by the mirrors together .

SolutioN :-

Fir figure refer to attachment . So from Figure ,

• The deviation produced by 1st mirror = 180°-2a

• The deviation produced by 2nd mirror = 180°-2ß

Also in ∆ABC:-

⇒ θ + 90° - α + 90° - β = 180°

⇒ α + β = θ

Hence ,

$\sf:\implies\delta_{(net)}= 180^o-2\alpha +180^o -2\beta \\\\\sf:\implies \delta_{(net)}= 360^o -2(\alpha+\beta) \\\\\sf:\implies \pink{\delta_{(net)}= 360^o - 2\theta }$

Answer 2

Answer :-

When two mirrors are inclined at an angle ∅ (theta) , then the net deviation is 360°-2∅.