Physics - Magnetism Question with Solution | TestHub

The magnetic field at the centre of a circular arc subtending an angle $\theta$ at the centre is given by

$B=\frac{{\mu }_{0}i}{4\pi r}\theta$

Given that the angle subtended by the arc is $\theta =\frac{\pi }{5}$ radian.

Substituting the value of $\theta$ in the formula, we get

$B=\frac{{\mu }_{0}i}{4\pi r}\times \frac{\pi }{5}$

$B=\frac{{\mu }_{0}i}{20r}$

Answer: $\frac{{\mu }_{0}i}{20r}$