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COMEDK · Physics · 21. Magnetic Effects of Current

Current \(I\) is flowing in a conductor shaped as shown in the figure. The radius of the curved part is \(r\) and the length of straight portion is very large. The value of the magnetic field at the centre \(O\) will be


  1. A \(\frac{\mu_{0} I}{4 \pi r}\left(\frac{3 \pi}{2}+1\right)\)
  2. B \(\frac{\mu_{0} I}{4 \pi r}\left(\frac{3 \pi}{2}-1\right)\)
  3. C \(\frac{\mu_{0} I}{4 \pi r}\left(\frac{\pi}{2}+1\right)\)
  4. D \(\frac{\mu_{0} I}{4 \pi r}\left(\frac{\pi}{2}-1\right)\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(\frac{\mu_{0} I}{4 \pi r}\left(\frac{3 \pi}{2}+1\right)\)

Step-by-step Solution

Detailed explanation

The given current carrying conductor is shown below Magnetic field at the centre due to circular wire, \[ B_{1}=\frac{\mu_{0} I}{2 r} \times \frac{270}{360}=\frac{\mu_{0} I}{2 r} \times \frac{3}{4} \] \[ B_{1}=\frac{3 \mu_{0} I}{8 r} \] [in downward to the plane of paper]…