1. Tardigrade
  2. Question
  3. Physics
  4. A concave lens of focal length (1/3) m forms a real, inverted image twice in size of the object. The distance of the object from the lens is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. A concave lens of focal length $\frac{1}{3} \,m$ forms a real, inverted image twice in size of the object. The distance of the object from the lens is

Ray Optics and Optical Instruments

Solution:

$m=\frac{m}{f+u}$
$-2=\frac{\frac{1}{3}}{\frac{1}{3}+u}$
$-\frac{2}{3}-2 u=\frac{1}{3}$
or $-2 u=\frac{1}{3}+\frac{2}{3}=1$ or $u=-\frac{1}{2} m =-0.5 m$