A ray reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of 240° . Then, the number of images observable is

Question

A ray reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of 240° . Then, the number of images observable is (A) 3 (B) 5 (C) 7 (D) 9

Tardigrade Admin · Accepted Answer

D=360° -2θ , 240° =360° -2θ 2θ =120° , ∴ θ =60° Then, number of images observable N=(360° /60° )-1 N=6-1 N=5

Q. A ray reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of $240^{\circ}$ . Then, the number of images observable is

3

5

7

9

$D = 360^{\circ} - 2 θ,$ $240^{\circ} = 360^{\circ} - 2 θ$ $2 θ = 120^{\circ},$ $∴$ $θ = 60^{\circ}$ Then, number of images observable $N = \frac{360 ^{\circ}}{60 ^{\circ}} - 1$ $N = 6 - 1$ $N = 5$

Q. A ray reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of 240∘ . Then, the number of images observable is

3

5

7

9

D=360∘−2θ, 240∘=360∘−2θ 2θ=120∘, ∴ θ=60∘ Then, number of images observable N=60∘360∘​−1 N=6−1 N=5

Q. A ray reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of $240^{\circ}$ . Then, the number of images observable is

$D = 360^{\circ} - 2 θ,$ $240^{\circ} = 360^{\circ} - 2 θ$ $2 θ = 120^{\circ},$ $∴$ $θ = 60^{\circ}$ Then, number of images observable $N = \frac{360 ^{\circ}}{60 ^{\circ}} - 1$ $N = 6 - 1$ $N = 5$