1. Tardigrade
  2. Question
  3. Physics
  4. Two thin lenses of powers 12 D and -2D respectively are placed in contact, the power focal length and nature respectively will be:

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. Two thin lenses of powers $12 \,D$ and $-2D$ respectively are placed in contact, the power focal length and nature respectively will be:

JIPMERJIPMER 2004

Solution:

Given : $P_{1}=12\, D,\, P_{2}=-2\, D$
Power of combination
$P=P_{1}+P_{2}=12-2=10\, D$
Focal length $f=\frac{1}{P}=\frac{1}{10} m =0.1\, m$
The combined lens will be convex (convergent)