Two mirrors are inclined at an angle θ as shown in the figure Light ray is incident parallel to - Physics - Ray Optics And Optical Instruments

Question

Two mirrors are inclined at an angle θ as shown in the figure
Light ray is incident parallel to one of the mirrors Light will
start retracing its path after third reflection if : (A) θ =
45° (B) θ = 30° (C) θ = 60° (D) all
three

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Ujjval Chauhan · Accepted Answer

Dear student,

<img alt="" src=
"https://s3mn%20mnimgs%20com/img/shared/ck-files/ck_577a6b24eb779%20png"
style="width: 355px; height: 213px;">
In, ∆ABC,θ+θ+θ+90°=180°⇒θ=30°
So, the correct option is (B)

Regards

Two mirrors are inclined at an angle θ as shown in the figure. Light ray is incident parallel to one of the mirrors. Light will start retracing its path after third reflection if : (A) θ = 45° (B) θ = 30° (C) θ = 60° (D) all three ​

Two mirrors are inclined at an angle θ as shown in the figure. Light ray is incident parallel to one of the mirrors. Light will start retracing its path after third reflection if : (A) θ = 45° (B) θ = 30° (C) θ = 60° (D) all three