1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Doubt with power of lens with 2 media

  1. Aug 16, 2010 #1
    This is more of a general question.

    Suppose there is a biconvex lens(Radii are R1 and R2) with Refractive index =n2,it is bounded on 2 sides by media of RI=n1,n3.
    Now if I have to find its focal length,
    Is it correct?

    Suppose it were correct,
    If there is a biconvex lens with radii of curvatures R,with refractive index(RI)=n2 and surrounded by medium of RI=n1,then its power is,(n2/n1-1)(2/R)(Lens maker formula).Correct?
    But if we consider individual surfaces and use Power=(n2-n1)/R for 1rst and (n1-n2)/R for the second surface,and add them,I get Power=(n2-n1)(2/R).The two are different.
    Now where did i go wrong?

    Or should it be used like(I read in many places):
    Please explain.
    I am seriously confused:(.
    I would explain more if didn't understand.
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted

Similar Threads - Doubt power lens Date
Temperature multiplied by Power? 7 minutes ago
Doubt in electromagnetic induction Feb 23, 2018
Doubt on conservation of angular momentum Nov 3, 2017