A square loop of side $2\, a ,$ and carrying current I, is kept in $XZ$ plane with its centre at origin. A long wire carrying the same current $I$ is placed parallel to the $z-$axis and passing through the point $(0, b, 0),(b>>a)$. The magnitude of the torque on the loop about $z-$axis is given by:
  • A$\frac{2 \mu_{0} I^{2} a^{2}}{\pi b}$
  • B$\frac{\mu_{0} I^{2} a^{3}}{2 \pi b^{2}}$
  • C$\frac{\mu_{0} I^{2} a^{2}}{2 \pi b}$Z
  • D$\frac{2 \mu_{0} I^{2} a^{3}}{\pi b^{2}}$
JEE MAIN 2020, Diffcult
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