Question

A conductor in the shape of a square of edge length $l=0.4m$ carries a current $i=10.0A.$ Calculate the magnitude and direction of magnetic field at the centre of the square.

Answer 1

From screw law, we can see that direction of magnetic field at centre of the square is inwards as the current is clockwise.
$B=4(\frac{{\mu }_o}{4\pi }\frac{i}{r}\left)\right(sin\alpha +sin\beta )$

$=\frac{4\times {10}^{-7}\times 10}{0.2}(sin{45}^o+sin{45}^o)$

$=2.83\times {10}^{-5}T$ into the page