LIVE Course for free

Rated by 1 million+ students
Get app now
JEE MAIN 2023
JEE MAIN 2023 TEST SERIES
NEET 2023 TEST SERIES
NEET 2023
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
1.5k views
in Physics by (63.9k points)

An achromatic lens of focal length 100 cm is made up of crown and flint glass lenses. Find the focal length of each lens. Given that for crown glass 1.5245, µv = µr = 1.5155 and for flint glass µv = 1.659 and µr = 1.641.

1 Answer

+1 vote
by (57.9k points)
selected by
 
Best answer

The focal length of the combination of lens is given by 1/F = 1/f1 + 1/f2

If µ and µ’ are mean refractive indices for crown and flint glasses, respectively, then,

The dispersive powers ω and ω' for crown and flint glass, respectively, are 

To have an achromatic combination,

The achromatic doublet requires a convex lens of focal length 37.5 cm made of crown glass and a concave lens of focal length 60 cm made of flint glass.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...