The focal length of a plane mirror is .......

Two mirrors,labeled $LM$ for left mirror and $RM$ for right mirror in the adjacent figure,are parallel to each other and $3.0 \, m$ apart. $A$ person standing $1.0 \, m$ from the right mirror $(RM)$ looks into this mirror and sees a series of images. How far from the person is the second closest image seen in the right mirror $(RM)$ (in $, m$)?

If an observer is walking away from a plane mirror with a velocity of $6\;m/s$,then the velocity of the image with respect to the observer will be........$m/s$.

$A$ mirror is placed at an angle of $30^{\circ}$ with respect to the $Y$-axis (see figure). $A$ light ray travelling in the negative $y$-direction strikes the mirror. The direction of the reflected ray is given by the vector

Two plane mirrors $A$ and $B$ are placed parallel to each other as shown in the figure. $A$ light ray is incident on mirror $A$ at an angle of $30^o$. The plane of incidence coincides with the plane of the figure. What is the maximum number of reflections (including the first one) the ray will undergo before emerging?

Two mirrors at an angle $\theta^{\circ}$ produce $5$ images of a point. The number of images produced when $\theta$ is decreased to $\theta^{\circ}-30^{\circ}$ is