Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Medical
  • A long straight wire of radius a carries a steady current I. The current is uniformly distributed over its cross-section. The ratio of the magnetic fields B and B', at radial distances a/2 and

A long straight wire of radius a carries a steady current I. The current is uniformly distributed over its cross-section. The ratio of the magnetic fields B and B', at radial distances a/2 and 2a respectively, from the axis of the wire is :

Option: 1

\frac{1}{4}


Option: 2

\frac{1}{2}


Option: 3

1


Option: 4

4


Answers (1)

best_answer

For points inside the wire i.e., (r, R) 

Magnetic field \mathrm{B=\frac{\mu_0 \mathrm{Ir}}{2 \pi \mathrm{R}^2}}

For points outside the wire \mathrm{(r~ R)}  Magnetic field,  \mathrm{B^{\prime}=\frac{\mu_0 I}{2 \pi R}} 
\mathrm{ \therefore \frac{B}{B^{\prime}}=\frac{\frac{\mu_0 1\left(\frac{a}{2}\right)}{2 \pi^2}}{\frac{\mu_0 1}{2 \pi(2 a)}}=1: 1 }

Posted by

Gaurav

View full answer

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks

Similar Questions

Trending Articles/News

anam-khan

NEET UG 2025: SC dismisses plea claiming error in three questions, directs petitioner to HC
anam-khan

Same seat, two prices? KEA lists SMSIMSR MBBS fee as Rs 22 lakh for private quota, college says Rs 25L
anam-khan

Maharashtra NEET counselling 2025 registration extended; CAP round 1 MBBS, BDS selection list on August 11

Latest Question