$A$ candle flame of $3\, cm$ is placed at $3\, m$ from a wall. $A$ concave mirror is kept at a distance $x$ from the wall in such a way that the image of the flame on the wall is $9\, cm$. Then $x$ is......$cm$.

$A$ point source is situated at a distance $x < f$ from the pole of a concave mirror of focal length $f$. At time $t = 0$,the point source starts moving away from the mirror with constant velocity. Which of the graphs below represents best the variation of image distance $|v|$ with the distance $x$ between the pole of the mirror and the source?

$A$ person looks at the image of two parallel finite length lines $PQ$ and $RS$ in a convex mirror (see figure). Which of the following represents schematically the image correctly? Note: Letters $P, Q, R$ and $S$ are used only to denote the endpoints of the lines.

An object of height $5 \, cm$ is placed at a distance of $1 \, m$ from a concave mirror of radius of curvature $20 \, cm$. What will be the height of the image in $cm$?

$A$ short straight object of length $l$ lies along the central axis of a spherical concave mirror, at a distance $X$ from the mirror. The focal length of the mirror is $F$. If the length of the image in the mirror is $l^{\prime}$, then the ratio $\left(\frac{l^{\prime}}{l}\right)$ is (assume $l << X$ and $l << F$):

An object is placed at a distance $u$ from a concave mirror of focal length $f$. $A$ real image is formed on a screen placed at a distance $v$ from the mirror. As $u$ changes,$v$ also changes. Which of the following graphs correctly represents the variation of $1/v$ with $1/u$?