Question

An object is plaved at a distance of 40 cm from a concave mirror of focal length 10 cm. What is the image distance for the given situation?

• A. 10 cm
• B. -10 cm
• C. 8 cm
• D. -8 cm

Answer 1

The correct option is C

8 cm

f=-10 cm
Applying lens formular;
$\frac{1}{v}-\frac{1}{u}=\frac{1}{f}$ we get;
$\frac{1}{v}=\frac{1}{f}+\frac{1}{u}=\frac{-1}{10}-\frac{1}{40}=\frac{1}{8}\Rightarrow v=8cm.$