Question

Consider the current carrying loop shown in figure formed of radial lines and segments of circles whose centre are at point P.Find the magnitude and direction of $\overrightarrow{B}$ at point P.

Answer 1

Magnetic field at P due to straight wires $=0$
Due to circular wires one is outwards (of radius a) and other is inwards ${60}^o$ means $\frac{1}{6}$th of whole circle.
$\therefore B=\frac{1}{6}[\frac{{\mu }_{o}i}{2a}-\frac{{\mu }_{o}i}{2b}]$ (outwards)