An object is placed at a distance of $f$ from the pole of a convex mirror of focal length $f$. Where will the image be formed?

The shape of the image formed of an object $AB$ due to the concave mirror shown in the figure is best represented by (assume point $A$ is at the centre of curvature of the mirror):-

$A$ convex mirror has a focal length $f$. $A$ real object is placed at a distance $f$ in front of it from the pole. The image is produced at:

$A$ student performed the experiment of determination of focal length of a concave mirror by $u-v$ method using an optical bench of length $1.5 \ m$. The focal length of the mirror used is $24 \ cm$. The maximum error in the location of the image can be $0.2 \ cm$. The $5$ sets of $(u, v)$ values recorded by the student (in $cm$) are: $(42, 56), (48, 48), (60, 40), (66, 33), (78, 39)$. The data set$(s)$ that cannot come from the experiment and is (are) incorrectly recorded,is (are):
$(A) (42, 56)$
$(B) (48, 48)$
$(C) (66, 33)$
$(D) (78, 39)$

$A$ man having height $6 \ m$ observes an erect image of height $2 \ m$. The mirror used 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?