Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
Two very long, straight, parallel conductors A and $\mathrm{B}$ carry current of $5 \mathrm{~A}$ and $10 \mathrm{~A}$ respectively and are at a distance of $10 \mathrm{~cm}$ from each other. The direction of current in two conductors is same. The force acting per unit length between two conductors is $\left(\mu_0=4 \pi \times 10^{-7}\right.$ SI unit):
PhysicsMagnetic Effects of CurrentNEETNEET 2022 (Phase 2)
Options:
  • A $2 \times 10^{-4} \mathrm{Nm}^{-1}$ and is attractive
  • B $2 \times 10^{-4} \mathrm{Nm}^{-1}$ and is repulsive
  • C $1 \times 10^{-4} \mathrm{Nm}^{-1}$ and is attractive
  • D $1 \times 10^{-4} \mathrm{Nm}^{-1}$ and is repulsive
Solution:
2904 Upvotes Verified Answer
The correct answer is: $1 \times 10^{-4} \mathrm{Nm}^{-1}$ and is attractive
As per question,
$\begin{aligned}
\frac{\mathrm{F}}{l} & =\frac{\mu_{\mathrm{o}}}{4 \pi} \times \frac{2 \mathrm{I}_1 \mathrm{I}_2}{r} \\
& =\frac{4 \pi \times 10^{-7} \times 2 \times 5 \times 10}{2 \pi \times 0.1} \\
& =10^{-4} \mathrm{Nm}^{-1}
\end{aligned}$
The nature of the force is attractive.
(where, the symbols have their usual meanings)

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.