The magnetic field at the origin due to the current flowing in the wire is
$ - \frac{{{\mu _0}I}}{{8\pi a}}\left( {\hat i + \hat k} \right)$
$\frac{{{\mu _0}I}}{{2\pi a}}\left( {\hat i + \hat k} \right)$
$\frac{{{\mu _0}I}}{{8\pi a}}\left( { - \hat i + \hat k} \right)$
$\frac{{{\mu _0}I}}{{4\pi a\sqrt 2 }}\left( {\hat i - \hat k} \right)$
A circular loop is kept in that vertical plane which contains the north-south direction. It carries a current that is towards south at the topmost point. Let $A$ be a point on axis of the circle to the east of it and $B$ a point on this axis to the west of it. The magnetic field due to the loop :-
A tightly wound $100$ turns coil of radius $10 \mathrm{~cm}$ carries a current of $7 \mathrm{~A}$. The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as $4 \pi \times 10^{-7} \mathrm{SI}$ units):
Magnetic field vector component because of ...... and electric field scalar component because of ......
A circular loop of radius $r$ is carrying current I A. The ratio of magnetic field at the centre of circular loop and at a distance $r$ from the center of the loop on its axis is:
In figure two parallel infinitely long current carrying wires are shown. If resultant magnetic field at point $A$ is zero. Then determine current $I.$ (in $A$)