A current loop, having two circular arcs joined by two radial lines is shown in the figure. It carries a current of $10\, A$. The magnetic field at point $O$ will be close to
$1.0 \times {10^{ - 7}}\,T$
$1.5 \times {10^{ - 7}}\,T$
$1.5 \times {10^{ - 5}}\,T$
$1.0 \times {10^{ - 5}}\,T$
A portion of a conductive wire is bent in the form of a semicircle of radius $r$ as shown below in fig. At the centre of semicircle, the magnetic induction will be
A parallel plate capacitor of area $60\, cm^2$ and separation $3\, mm$ is charged initially to $90\, \mu C$. If the medium between the plate gets slightly conducting and the plate loses the charge initially at the rate of $2.5\times10^{-8}\, C/s$, then what is the magnetic field between the plates ?
A current of $i$ ampere is flowing through each of the bent wires as shown the magnitude and direction of magnetic field at $O$ is
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
In figure two parallel infinitely long current carrying wires are shown. If resultant magnetic field at point $A$ is zero. Then determine current $I.$ (in $A$)