Physics Circle home Student Login

Home›Chapters›Moving Charges and Magnetism PYQs›Magnetic Field of Straight Wires›Question 52

JEE Main 2021 (17 Mar, Shift 2) · Magnetic Field of Straight Wires

Magnetic Field of Straight Wires question from JEE Main 2021 (17 Mar, Shift 2)

Q52JEE Main 2021 · 17 MAR · SHIFT 2Medium

Magnetic Field of Straight Wires

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 P which lies on the centre of the semicircle?

Figure

Show answer and solution

Answer: (c)

  1. Each semi-infinite straight wire ends at the foot of the perpendicular from P: μ0I4πr\frac{\mu_0 I}{4\pi r} each, both into the page.
  2. Semicircle (clockwise): μ0I4r=μ0I4πrπ\frac{\mu_0 I}{4r} = \frac{\mu_0 I}{4\pi r}\pi, also into the page.
  3. B=μ0I4πr(2+π)B = \frac{\mu_0 I}{4\pi r}(2 + \pi)
  4. So the answer is (c).
Report a mistake

More questions on Magnetic Field of Straight Wires