Question

A current I flows in circular arc of wire which subtends an angle ${\theta }^{\circ }$ at the centre. If the radius of the circle is r then the magnetic field B at center is:

• A. $\frac{{\mu }_{0}i}{r}$
• B. $\frac{{\mu }_{0}i}{2r}$
• C. $\frac{3{\mu }_{0}i}{4r}$
• D. $\frac{\left(\frac{{\theta }^{\circ }}{{360}^{\circ }}\right){\mu }_{0}i}{2r}$

Answer 1

The correct option is D $\frac{\left(\frac{{\theta }^{\circ }}{{360}^{\circ }}\right){\mu }_{0}i}{2r}$

$B=\frac{{\mu }_{0}i}{4\pi r}\left[\theta \right]$

$B=\frac{\left(\frac{{\theta }^{\circ }}{360}\right){\mu }_{0}i}{2r}$