Rays of light strike a horizontal plane mirror at an angle of 45°. A second plane mirror is arranged at an angle θ with it. If the ray after reflection from the second mirror goes horizontally parallel to the first mirror then θ is (in degree)

Question

Rays of light strike a horizontal plane mirror at an angle of 45°. A second plane mirror is arranged at an angle θ with it. If the ray after reflection from the second mirror goes horizontally parallel to the first mirror then θ is (in degree) (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/8870faafe70537155774a8e3d1ca263d-.png" /> From triangle AOB, θ+θ+45°=180° θ=(135°/2)=67.5°

Q. Rays of light strike a horizontal plane mirror at an angle of $4 5^{\circ}$ . A second plane mirror is arranged at an angle $θ$ with it. If the ray after reflection from the second mirror goes horizontally parallel to the first mirror then $θ$ is (in degree)

From $△ A OB$ ,
$θ + θ + 4 5^{\circ} = 18 0^{\circ}$
$θ = \frac{13 5 ^{\circ}}{2} = 67. 5^{\circ}$

Q. Rays of light strike a horizontal plane mirror at an angle of 45∘. A second plane mirror is arranged at an angle θ with it. If the ray after reflection from the second mirror goes horizontally parallel to the first mirror then θ is (in degree)

From △AOB, θ+θ+45∘=180∘ θ=2135∘​=67.5∘

Q. Rays of light strike a horizontal plane mirror at an angle of $4 5^{\circ}$ . A second plane mirror is arranged at an angle $θ$ with it. If the ray after reflection from the second mirror goes horizontally parallel to the first mirror then $θ$ is (in degree)

From $△ A OB$ ,
$θ + θ + 4 5^{\circ} = 18 0^{\circ}$
$θ = \frac{13 5 ^{\circ}}{2} = 67. 5^{\circ}$