Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • Two metallic wires of identical dimensions are connected in series. If <img alt="\sigma_{1}$ and $\sigma_{2}" src="https://entrancecorner.oncodecogs.com/gif.latex?%5Csigma_%7B1%7D%24%20and%20%24%5C

Two metallic wires of identical dimensions are connected in series. If \sigma_{1}$ and $\sigma_{2} are the conductivities of the these wires respectively, the effective conductivity of the combination is :
 

Option: 1

\frac{\sigma_{1} \sigma_{2}}{\sigma_{1}+\sigma_{2}}


Option: 2

\frac{2 \sigma_{1} \sigma_{2}}{\sigma_{1}+\sigma_{2}}


Option: 3

\frac{\sigma_{1}+\sigma_{2}}{2 \sigma_{1} \sigma_{2}}


Option: 4

\frac{\sigma_{1}+\sigma_{2}}{\sigma_{1} \sigma_{2}}


Answers (1)

best_answer

For wire in series combination

\mathrm{R_{\text {eff }} =R_1+R_2 }

\mathrm{\frac{2 \ell}{\sigma_{\text {eff }} A} =\frac{\ell}{\sigma_1 A}+\frac{\ell}{\sigma_2 A} }

\mathrm{\sigma_{\text {eff }} =\frac{2 \sigma_1 \sigma_2}{\sigma_1+\sigma_2}}

Hence 2 is correct option

Posted by

Ritika Jonwal

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: BTech ECE cut-offs for female candidates go up at top NITs
anam-khan

JEE Main 2025 Session 2 City Slip (OUT) Live: Admit card likely on March 29 at jeemain.nta.nic.in; cut-offs
anam-khan

AESL expands Aakash Digital 2.0 to offer AI-powered coaching for NEET, JEE, Olympiads

Latest Question