ExamBro
ExamBro
MHT CET · Physics · Magnetic Effects of Current

A long straight wire of radius 'r' carries a steady current 'I'. The current is uniformly distributed over its cross-section. The ratio \(\left(\frac{B}{B^1}\right)\) of the magnetic field ' \(B\) ' and ' \(B^1\) ' it radial distances \(\frac{r}{2}\) ' and ' \(3 r\) ' respectively, from the axis of the wire is

  1. A \(\frac{1}{2}\)
  2. B \(\frac{3}{2}\)
  3. C \(\frac{5}{2}\)
  4. D \(\frac{7}{2}\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(\frac{3}{2}\)

Step-by-step Solution

Detailed explanation

\( B = \frac{\mu_0 I (r/2)}{2 \pi r^2} = \frac{\mu_0 I}{4 \pi r} \) \( B' = \frac{\mu_0 I}{2 \pi (3r)} = \frac{\mu_0 I}{6 \pi r} \)
Same subject
Explore more questions on app