Ray Optics Question 8
Question 8 - 2024 (30 Jan Shift 1)
The distance between object and its two times magnified real image as produced by a convex lens is $45 \mathrm{~cm}$.
The focal length of the lens used is $\mathrm{cm}$.
Show Answer
Answer: (10)
Solution:
$\frac{v}{u}=-2$
$v=-2 u$
$v-u=45$
$\Rightarrow u=-15 \mathrm{~cm}$
$v=30 \mathrm{~cm}$
$\frac{1}{f}=\frac{1}{v}-\frac{1}{u}$
$f=+10 \mathrm{~cm}$
