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
A point charge $Q\left(=3 \times 10^{-12} C \right)$ rotates uniformly in a vertical circle of radius $R(=1 \,mm )$. The axis of the circle is aligned along the magnetic axis of the earth. At what value of the angular speed $\omega$, the eff ective magnetic field at the centre of the circle .............. $rad / s$ will be reduced to zero? (Horizontal component of earth's magnetic field is $30 \,\mu T )$
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:
Write Biot-Savart law.
An element $d l=d x \hat{l}$ (where, $d x=1\, cm$ ) is placed at the origin and carries a large current $i=10 A$. What is the magnetic field on the $Y$ -axis at a distance of $0.5\, m$ ?
Give definition of $1\, \mathrm{T}$ magnetic field.