Power of a plane mirror is . . . . . .

$A$ light ray is incident on a plane mirror at an angle of incidence of $30^\circ$. The deviation produced by the mirror is ........$^\circ$.

Assertion : If the angle between the two plane mirrors is $72^o$ and the object is asymmetrically placed between the two mirrors,then $5$ images of the object will be formed.
Reason : For a given system of mirrors,the total number of images formed due to successive reflection is equal to either $\frac{360^o}{\theta}$ or $\frac{360^o}{\theta} - 1$ accordingly as $\frac{360^o}{\theta}$ is odd or even respectively.

Two plane mirrors are inclined to one another at an angle of $60^o$. $A$ ray is incident on mirror $M_1$ at an angle $i$. The reflected ray from mirror $M_1$ is shown in the figure. The angle of incidence $i$ is (in $^o$)

$A$ light bulb is placed between two plane mirrors inclined at an angle of $60^{\circ}$. The number of images formed is:

$A$ flat mirror $M$ is arranged parallel to a wall $W$ at a distance $l$ from it. The light produced by a point source $S$ kept on the wall is reflected by the mirror and produces a light spot on the wall. The mirror moves with velocity $v$ towards the wall.