Question

A circular wire of radius r carries a current i. If the magnitude of magnetic field at the center is B, then the value of i is

• A. $\frac{2\pi Br}{{\mu }_o}$
• B. $\frac{Br}{{\mu }_o}$
• C. $\frac{\pi Br}{{\mu }_o}$
• D. $\frac{2Br}{{\mu }_o}$

Answer 1

Answer: (D)

$B=\frac{{\mu }_{o}i}{2r}$
$I=\frac{2Br}{{\mu }_o}$