A particle is moving with velocity $\overrightarrow{ v }=\hat{ i }+3 \hat{ j }$ and it produces an electric field at a point given by $\overrightarrow{ E }=2 \hat{ k }$. It will produce magnetic field at that point equal to (all quantities are in SI units)
$\frac{6 \hat{ i }-2 \hat{ j }}{ c ^2}$
$\frac{6 \hat{i}+2 \hat{j}}{c^2}$
$zero$
cannot be determined from the given data
A current $I$ flows around a closed path in the horizontal plane of the circle as shown in the figure. The path consists of eight arcs with alternating radii $r$ and $2r$. Each segment of arc subtends equal angle at the common centre $P.$ The magnetic field produced by current path at point $P$ is
If an electron revolves around a nucleus in a circular orbit of radius $R$ with frequency $n$, then the magnetic field produced at the centre of the nucleus will be
A uniform wire is bent in the form of a circle of radius $R$. A current $I$ enters at $A$ and leaves at $C$ as shown in the figure :If the length $ABC$ is half of the length $ADC,$ the magnetic field at the centre $O$ will be
A coil having $N$ $turns$ is wound tightly in the form of a spiral with inner and outer radii $a$ and $b$ respectively. When a current $I$ passes through the coil, the magnetic field at the centre is
The magnetic field at the centre of a circular current carrying-conductor of radius $r$ is $B_c$. The magnetic field on its axis at a distance $r$ from the centre is $B_a$. The value of $B_c : B_a$ will be :-