Question

A convex lens of power +5D was used to produce a virtual magnified image 5 times the size of the object. Determine the object and image position

Answer 1

let $d_1$ be a distance from object to lens, and $d_2$ be a distance from image to lens.

then

$\begin{cases} \Gamma = \frac{h_2}{h_1} = \frac{d_2}{d_1} = 5\\ \frac{1}{F}=\frac{1}{d_1}+\frac{1}{d_2} = 5 \end{cases} \Rightarrow \begin{cases} d_2=5d_1\\ \frac{6}{5}=5d_1 \end{cases} \Rightarrow \begin{cases} d_2=1.2 m\\ d_1 = 0.24m \end{cases}$