$A$ 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.

Incident parallel rays make an angle of $5^{\circ}$ with the axis of a concave mirror of focal length $20 \ cm$. The perpendicular distance of the image from the axis is nearly $-$ (in $cm$)

The direction of a ray of light incident on a concave mirror is shown by $PQ$,while the directions in which the ray would travel after reflection are shown by four rays marked $1, 2, 3,$ and $4$. Which of the four rays correctly shows the direction of the reflected ray?

$A$ small linear object of length $b$ is placed on the axis of a concave mirror of focal length $f$ at a distance $u$ from its pole. What is the approximate length of the image?

$A$ concave mirror of focal length '$f$' produces an image '$n$' times the size of the object. If the image is real, then the distance of the object from the mirror is

$A$ small candle,$2.5\; cm$ in size,is placed at $27\; cm$ in front of a concave mirror of radius of curvature $36\; cm$. At what distance from the mirror should a screen be placed in order to obtain a sharp image? Describe the nature and size of the image. If the candle is moved closer to the mirror,how would the screen have to be moved?