Question

The magnetic field at the centre ‘O’ in the given figure is

• A. $\frac{3}{10}\frac{{\mu }_{0}I}{R}$
• B. $\frac{7}{14}\frac{{\mu }_{0}I}{R}$
• C. $\frac{{\mu }_{0}I}{12R}$
• D. $\frac{5}{12}\frac{{\mu }_{0}I}{R}$

Answer 1

Answer: (D)

$Here\theta =300^{\circ }$
$\therefore Numberofturnsn=\frac{300}{360}=\frac{5}{6}$
$B={\mu }_0\frac{nI}{2R}i.e.,{\mu }_0\frac{5}{6}\times \frac{I}{2R}$
$\therefore B=\frac{5{\mu }_{0}I}{12R}$