$A$ wall clock has marks instead of numbers. It is placed opposite to a mirror. The time observed in the mirror reflection is $8:20$. What is the actual time on the clock?

The coordinate of the image with respect to the origin $c$ will be:

As shown in the figure,a particle is placed at $O$ in front of a plane mirror $M$. $A$ man at $P$ can move along the path $PY$ and $PY'$. Which of the following is true?

$A$ two-eyed man is looking at the junction of two mutually perpendicular mirrors from a far-off distance. Assume no reflection occurs from the edge. If both eyes are open,then:

$A$ cubical room is formed with $6$ plane mirrors. An insect moves along the diagonal of the floor with uniform speed $v_0$. The speed of its image in two adjacent walls,parallel to the walls,is $20\sqrt{2} \ cm/s$. Then the speed of the image formed on the roof with respect to the ground is ...... $cm/s$.

$A$ light beam is being reflected by using two mirrors,as in a periscope used in submarines. If one of the mirrors rotates by an angle $\theta$,the reflected light will deviate from its original path by the angle