Question

A small object stuck on the surface of a glass sphere $(\mu =1.5)$ is viewed from the diametrically opposite position.


Considering the proper sign convention,find the position of image for given observer.

Answer 1

Incident ray originating from object $O$ is going towards right direction.

For observer,
$u=-2R;R=-R$

Here incident ray is travelling through medium of ${\mu }_1=1.5$ and observer is in air (${\mu }_2=1$)

And we know that,
$\frac{{\mu }_2}{v}-\frac{{\mu }_1}{u}=\frac{{\mu }_2-{\mu }_1}{R}$

$\Rightarrow \frac{1}{v}-\frac{1.5}{-2R}=\frac{1-1.5}{-R}$

$\Rightarrow \frac{1}{v}=\frac{-1}{4R}$

$\therefore v=-4R$

so, the position of image will be at a distance of 2R towads left from its original position.