A wire bent in the shape of a regular n polygonal loop carries a steady current I. Let 1 be the perpendicular distance of a given segment and $R$ be the distance of given segment and $R$ be the distance of a vertex both from the centre of the loop. The magnitude of the magnetic field at the centre of the loop is given by.

• Correct answer
  A

  $\frac{n \mu_{0} I}{2 \pi l} \sin (\pi / n)$
• B

  $\frac{n \mu_{0} I}{2 \pi R} \sin (\pi / n)$
• C

  $\frac{n \mu_{0} I}{2 \pi l} \cos (\pi / n)$
• D

  $\frac{n \mu_{0} I}{2 \pi R} \cos (\pi / n)$

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