Q108 / 120 · VITEEE 2018 · Physics

Find the magnetic field at $\mathrm{P}$ due to the arrangement shown Figure

  • Correct answer
    A
    $\frac{\mu_{0} i}{\sqrt{2} \pi d}\left(1-\frac{1}{\sqrt{2}}\right) \otimes$
  • B
    $\frac{2 \mu_{0} i}{\sqrt{2} \pi d} \otimes$
  • C
    $\frac{\mu_{0} i}{\sqrt{2} \pi d} \otimes$
  • D
    $\frac{\mu_{0} i}{\sqrt{2} \pi d}\left(1+\frac{1}{\sqrt{2}}\right) \otimes$

Solution

$B=2\left[\frac{\mu_{0}}{4 \pi} \cdot \frac{i}{d \cos 45^{\circ}}\left\{\sin \left(-45^{\circ}\right)+\sin 90^{\circ}\right\}\right]$ $=\frac{\mu_{0} i}{\sqrt{2} \pi d}\left[-\frac{1}{\sqrt{2}}+1\right] . \otimes$

Hence, the correct answer is option: 'A'.

More Magnetic Effects of Current Questions