In bio savart law direction of magnetic field is shown by $d\vec B = \frac{{{\mu _0}}}{{4\pi }}\frac{{I\overrightarrow {dl} \times \vec r}}{{{r^3}}}$
$\vec r \times I\overrightarrow {dl} $
$I\overrightarrow {dl} \times \vec r$
$(A)$ and $(B)$
None
Gauss is unit of which quantity
The magnitude of magnetic induction at mid-point $O$ due to current arrangement as shown in Fig will be
Give similarity between Biot-Savart law and electrostatic law of Coulomb.
Two circular coils $X$ and $Y$, having equal number of turns, carry equal currents in the same sense and subtend same solid angle at point $O$. If the smaller coil, $X$ is midway between $O$ and $Y$, then if we represent the magnetic induction due to bigger coil $Y$ at $O$ as $BY$ and that due to smaller coil $X$ at $O$ as $BX$ , then
A charge $q$ $coulomb$ moves in a circle at $n$ revolutions per second and the radius of the circle is $r$ $metre$. Then magnetic field at the centre of the circle is