Physics - Geometrical Optics Question with Solution | TestHub

For a real image produced by a convex lens, the magnification is $m=-n$.

The magnification formula in terms of focal length $f$ and object coordinate $u$ is given by:

$m=\frac{f}{f+u}$

Substituting $m=-n$:

$-n=\frac{f}{f+u}$

$-nf-nu=f$

$-nu=f(n+1)$

$u=-f\left(\frac{n+1}{n}\right)=-f\left(1+\frac{1}{n}\right)$

The distance of the object from the lens is the magnitude of $u$:

$|u|=f\left(1+\frac{1}{n}\right)$

Answer: $\mathrm{f}\left(1+\frac{1}{\mathrm{n}}\right)$