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
$\frac{3}{8}\,\frac{{{\mu _0}I}}{r}$; perpendicular to the plane of the paper and directed inward.
$\frac{3}{8}\,\frac{{{\mu _0}I}}{r}$; perpendicular to the plane of the paper and directed outward.
$\frac{1}{8}\,\frac{{{\mu _0}I}}{r}$ ; perpendicular to the plane of the paper and directed inward.
$\frac{1}{8}\,\frac{{{\mu _0}I}}{r}$; perpendicular to the plane of the paper and directed outward..
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):
A very long conducting wire is bent in a semicircular shape from $A$ to $B$ as shown in figure. The magnetic field at point $P$ for steady current configuration is given by:
State and explain Biot-Savart law for the magnetic field produced by a current element. Give the direction of magnetic field and define the unit of it
An arc of a circle of radius $R$ subtends an angle $\frac{\pi }{2}$ at the centre. It carries a current $i$. The magnetic field at the centre will be
Two concentric coils $X$ and $Y$ of radii $16 \,\,cm$ and $10 \,\,cm$ lie in the same vertical plane containing $N-S$ direction. $X$ has $20$ $turns$ and carries $16 \,\,A.$ $Y$ has $25$ $turns$ $\&$ carries $18\,A$. $X$ has current in anticlockwise direction and $Y$ has current in clockwise direction for an observer, looking at the coils facing the west. The magnitude of net magnetic field at their common centre is