Physics Circle home Student Login

Home›Chapters›Moving Charges and Magnetism PYQs›Magnetic Field of Straight Wires›Question 57

MHT CET 2019 (3 May, Shift 1) · Magnetic Field of Straight Wires

Magnetic Field of Straight Wires question from MHT CET 2019 (3 May, Shift 1)

Q57MHT CET 2019 · 3 MAY · SHIFT 1Medium

Magnetic Field of Straight Wires

Figure show the circular coil carrying current II kept very close but not touching at a point AA on a straight conductor carrying the same current II. The magnitude of magnetic induction at the centre of the circular coil will be

Figure

Show answer and solution

Answer: (a)

  1. Coil at its centre: B1=μ0I2rB_1 = \frac{\mu_0 I}{2r}.
  2. Long wire at distance rr from O: B2=μ0I2πrB_2 = \frac{\mu_0 I}{2\pi r}.
  3. Taking both fields in the same direction: B=μ0I2r+μ0I2πr=μ0I2r(1+1π)B = \frac{\mu_0 I}{2r} + \frac{\mu_0 I}{2\pi r} = \frac{\mu_0 I}{2r}\left(1 + \frac{1}{\pi}\right)
  4. So the answer is (a).
Report a mistake

More questions on Magnetic Field of Straight Wires