# An extended objected is placed perpendicular to principal axis of a concave mirror of radius of curvature 20 cm at a distance of 15 cm from pole. Find the lateral magnification produced

$(a)\;1 \\ (b)\;-2 \\ (c)\;2 \\ (d)\;-1$

$u=-15 \;cm$
$f=-10\;cm$
$\large\frac{1}{v} +\frac{1}{u}=\frac{1}{f}$
gives $v =-30\;cm$
$\therefore m=\large\frac{-v}{u}$
$\qquad=-2$
Hence b is the correct