Four identical mirrors are used to form a square arrangement as shown in top view of the figure. A ray starts from mid-point m of mirror AD and after two reflections, reaches corner D, then angle$\theta =co{t}^{-1}n$.Here n is

Q. Four identical mirrors are made to stand vertically to form a square arrangement as shown in a top view. A ray starts from the midpoint M of mirror AD and after two reflections reaches corner D. Then, angle $\theta$ must be

Q. Two plane mirrors are inclined at angle $\theta$ as shown in figure. If a ray parallel to $OB$ strikes the other mirror at $P$ and finally emerges parallel to $OA$ after two reflections, then $\theta$ is equal to

Q. Two plane mirrors are inclined at angle $\theta$ as shown in figure. If a ray parallel to $OB$ strikes the other mirror at $P$ and finally emerges parallel to $OA$ after two reflections, then $\theta$ is equal to

Q. Two plane mirrors are arranged at right angles to each other as shown in figure. A ray of light is incident on the horizontal mirror at an angle $\theta$ . For what value of $\theta$ the ray emerges parallel to the incoming ray after reflection from the vertical mirror?

Q. Two plane mirror are arranged at right angles to each other as shown in figure .A ray of light is incident on the horizontal mirror at an angle of $\theta$.For what value of $\theta$ the ray emerges parallel to the incoming ray after reflection from the vertical mirror?