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JEE Main 202117 MarchEvening Shift
Exam
JEE Main
Year
2021
Date
17 March
Shift
Evening Shift
Subject
Physics
Chapter
Magnetic Effects of Current

JEE Main 2021 · 17 March · Evening Shift · Physics · Magnetic Effects of Current

A hairpin like shape as shown in figure is made by bending a long...

A hairpin like shape as shown in figure is made by bending a long current carrying wire. What is the magnitude of a magnetic field at point PP which lies on the centre of the semicircle ?

A hairpin like shape as shown in figure is made by bending a long current carrying wire. What is the magnitude of a

Options

  1. Aμ0I4\pir(2−π)\dfrac{{\mu}_{0}I}{4\pir} ( 2 - \pi )
  2. Bμ0I4\pir(2+π)\dfrac{{\mu}_{0}I}{4\pir} ( 2 + \pi )
  3. Cμ0I2\pir(2+π)\dfrac{{\mu}_{0}I}{2\pir} ( 2 + \pi )
  4. Dμ0I2\pir(2−π)\dfrac{{\mu}_{0}I}{2\pir} ( 2 - \pi )

Correct answer

B. μ0I4\pir(2+π)\dfrac{{\mu}_{0}I}{4\pir} ( 2 + \pi )

Step-by-step solution

B=2×Bst.wire+BloopB = 2 \times {B}_{st . wire} + {B}_{loop}

B=2×μ0i4\pir+μ0i2r(π2π)B = 2 \times \dfrac{{\mu}_{0}i}{4\pir} + \dfrac{{\mu}_{0}i}{2r}\left(\dfrac{\pi}{2\pi}\right)

B=μ0i4\pir(2+π)B = \dfrac{{\mu}_{0}i}{4\pir} ( 2 + \pi )

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