Problem

A square loop of side

a

carries a current

I

. The magnetic field at the centre of the loop is a. -

\frac{2\mu_0 I\sqrt{2}}{\pi a}

b. -

\frac{\mu_0 I\sqrt{2}}{\pi a}

c. -

\frac{4\mu_0 I\sqrt{2}}{\pi a}

d. -

\frac{\mu_0 I}{\pi a}