Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • An achromatic convergent doublet of two lenses in contact has a power of . Th

An achromatic convergent doublet of two lenses in contact has a power of \mathrm{+ 2\ D}. The convex lens has power \mathrm{+ 5\ D}. What is the ratio of the dispersive powers of the convergent and divergent lenses?

Option: 1

2:5


Option: 2

3:5


Option: 3

5:2


Option: 4

5:3


Answers (1)

best_answer

The condition for achromatism is
\mathrm{\begin{aligned} & \mathrm{\omega_1 P_1+\omega_2 P_2=0} \\ &\mathrm{ \omega_1 P_1=-\omega_2 P_2 \Rightarrow \frac{\omega_1}{\omega_2}=-\frac{P_2}{P_1}} \end{aligned}}
\mathrm{Now, P_1+P_2=2 D\ or\ 5+P_2=2\ or\ P_2=-3 D} \\ \mathrm{\therefore \quad \frac{\omega_1}{\omega_2}=-\frac{-3}{5}=\frac{3}{5}}

Posted by

Nehul

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

JEE Main 2025 just a month away; section-wise preparation tips, important topics, tricks and strategies
anam-khan

JEE Main 2025: Hardwired to excel? Know BTech electrical engineering cut-offs at NITs
anam-khan

JEE Main 2025 chemistry needs conceptual understanding; 5 tips to score high

Latest Question