Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 12-science Answered

if for a perfectly symmertical lens, r1=r2, then how will we find focal length??
Asked by Dark | 05 Jan, 2022, 11:54: AM
Expert Answer
We have Lens maker's formula
 
begin mathsize 14px style 1 over f equals space open parentheses mu space minus space 1 close parentheses open parentheses 1 over r subscript 1 space minus space 1 over r subscript 2 close parentheses end style ............................... (1)
where f is focal length , μ is refractive index of materilal of lens , r1 is radius of curvature of left side
spherical surface and r2 is radius of curvature of right side spherical surface.

numerically r1 = r2 = r, by sign convention r1 is positive and r2 is negative .
 
Hence we get from eqn.(1)
 
begin mathsize 14px style f space equals space fraction numerator r over denominator 2 open parentheses mu minus 1 close parentheses end fraction end style
From the known value of radius of curvature and refractive index of material ,
we get focal length f from above expression
Answered by Thiyagarajan K | 05 Jan, 2022, 01:22: PM
CBSE 12-science - Physics
Asked by hanskaraja | 05 Aug, 2022, 11:20: PM
ANSWERED BY EXPERT
CBSE 12-science - Physics
Asked by Dark | 05 Jan, 2022, 11:54: AM
ANSWERED BY EXPERT
CBSE 12-science - Physics
Asked by nagendramanikireddy999999 | 29 May, 2021, 11:50: AM
ANSWERED BY EXPERT
CBSE 12-science - Physics
Asked by manjulamurali1979 | 19 May, 2020, 09:01: PM
ANSWERED BY EXPERT
CBSE 12-science - Physics
Asked by tyeswanthkumar37 | 14 May, 2020, 10:58: AM
ANSWERED BY EXPERT
CBSE 12-science - Physics
Asked by polyrelation | 15 Mar, 2019, 04:40: PM
ANSWERED BY EXPERT
CBSE 12-science - Physics
Asked by polyrelation | 15 Mar, 2019, 04:40: PM
ANSWERED BY EXPERT
CBSE 12-science - Physics
Asked by pradeepjsme | 30 Jan, 2019, 03:49: PM
ANSWERED BY EXPERT
CBSE 12-science - Physics
Asked by rohitraman1115 | 12 Jan, 2019, 12:19: PM
ANSWERED BY EXPERT
CBSE 12-science - Physics
Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM
ANSWERED BY EXPERT
Get Free Sample Papers
×