Question

A curved thick glass surface is silvered at curved face and is not silvered on plane surface. Object is placed at $A$ as shown in the figure. Consider $P$ (pole of the silvered surface) as origin. If $x$ co-ordinate of final image is $(2n)$. $cm$, then find $n$.

Answer 1

Answer: 7

$u=-\left(4+\frac{4}{2}\right)\times 2=-12cm$
$\frac{1}{v}+\frac{1}{-12}=\frac{1}{-8}$
$\Rightarrow v=-24cm$
For final image (refraction through plane surface), we can write
$24=2\left(\frac{x}{1}+\frac{4}{2}\right)$
$\Rightarrow 24=2x+4$
$x=10cm$
so, distance from $P$ is $14cm$.