Question

A convex mirror has a focal length $f$.A real object is placed at a distance $f$ in front of it from the pole, produces an image at:

• A. $\infty$
• B. $f$
• C. $\frac{f}{2}$
• D. $2f$

Answer 1

Answer: (C)

Given, Focal length $=f,u=-f$

By the mirror formula:

$\frac{1}{f}=\frac{1}{v}+\frac{1}{f}\Rightarrow \frac{1}{f}=\frac{1}{v}-\frac{1}{f}\Rightarrow \frac{1}{v}=\frac{2}{f}\Rightarrow v=\frac{f}{2}$