Question

A closely wounded circular coil of radius 5 cm produces a magnetic field of 37.68×10–4 T at its center. The current through the coil is _______ A.
[Given, number of turns in the coil is 100 and $\pi = 3.14$]

Answer 1

$B = \frac{\mu_0 n I}{2R}$
$37.68 \times 10^{-4} = \frac{4\pi \times 10^{-7} \times 100I}{2 \times 5 \times 10^{-2}}$

$I = \frac{300\, \text{A}}{100}$
$I= 3A$
So, the answer is 3A.