A semi circular arc of radius $r$ and a straight wire along the diameter, both are carrying same current $i.$ Find out magnetic force per unit length on the small element $P$, which is at the centre of curvature.
  • A$\left(\frac{\mu_{0} i^{2}}{4 r}\right)$
  • B$\left(\frac{\mu_{0} i^{2}}{2 r}\right)$
  • C$\left(\frac{\mu_{0} i^{2}}{r}\right)$
  • D$\left(\frac{2 \mu_{0} i^{2}}{r}\right)$
AIIMS 2019, Medium
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