Two similar coils are kept mutually perpendicular such that their centres coincide. At the centre, find the ratio of the magnetic field due to one coil and the resultant magnetic field by both coils, if the same current is flown
$1:$ $\sqrt 2 $
$1:2$
$2:1$
$\sqrt 3 \,\,:\,\,1$
Consider a tightly wound $100$ turn coil of radius $10 \;cm$, carrying a current of $1 \;A$. What is the magnitude of the magnetic field at the centre of the coil?
A long, straight wire is turned into a loop of radius $10\,cm$ (see figure). If a current of $8\, A$ is passed through the loop, then the value of the magnetic field and its direction at the centre $C$ of the loop shall be close to
A cylindrical cavity of diameter a exists inside a cylinder of diameter $2$a shown in the figure. Both the cylinder and the cavity are infinitely long. A uniform current density $J$ flows along the length. If the magnitude of the magnetic field at the point $P$ is given by $\frac{N}{12} \mu_0$ aJ, then the value of $N$ is :
A thin ring of $10\, cm$ radius carries a uniformly distributed charge. The ring rotates at a constant angular speed of $40\,\pi \,rad\,{s^{ - 1}}$ about its axis, perpendicular to its plane. If the magnetic field at its centre is $3.8 \times {10^{ - 9}}\,T$, then the charge carried by the ring is close to $\left( {{\mu _0} = 4\pi \times {{10}^{ - 7}}\,N/{A^2}} \right)$
In the above figure magnetic field at point $C$ will be