1. Tardigrade
  2. Question
  3. Physics
  4. A concave lens of focal length 20 cm product an image half in size of the real object. The distance of the real object is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. A concave lens of focal length $20 \, cm$ product an image half in size of the real object. The distance of the real object is

NTA AbhyasNTA Abhyas 2022Ray Optics and Optical Instruments

Solution:

We know that
$m=\frac{f}{f + u}$
$\frac{1}{2}=\frac{- 20}{- 20 + u} \, or-20+u=-40$
Or $ \, u=-40+20 \, $ or $ \, \, u=-20 \, cm$