Bibek Thakur

a ray reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of 300. Then the angle isa) 30 b) 60 c) 90 d 120

B A D= x

, ABD=yHere AD and BD are Normal lines,

O B A = 90 y

O A B = 90 x

Δ O A B;

θ + 90 y + 90 x = 180

x + y = θ

Total deviation is

2 (90 x) + 2 (90 y)

= 360 2 (x + y)

= 360 2 θ

Here from the question deviation angle is 300^olet, a be the angle between two plane mirror, therefore, 300^o = 360^o - 2a so, a= 30^o

Bibek Thakur

Reflection at Plane Surfaces

a ray reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of 300. Then the angle isa) 30 b) 60 c) 90 d 120