Physics - Geometrical Optics Question with Solution | TestHub

Consider the diagram below:Given, $v=(-D)$, Using mirror formula: $\frac{1}{v}-\frac{1}{u}=\frac{1}{f}$ $\begin{array}{rl}& \Rightarrow \frac{1}{(-D)}-\frac{1}{u}=\frac{1}{f}\\ & \Rightarrow \frac{1}{u}=-\left(\frac{f+D}{fD}\right)\end{array}$ Now, magnification can be easily calculated as: $\therefore m=\frac{v}{u}=\frac{(-D)(f+D)}{(-fD)}=\left(1+\frac{D}{f}\right)$