For adjoining fig., The magnetic field at point, $P$ will be
$\frac{\mu_0}{4 \pi} \odot$
$\frac{\mu_0}{\pi} \otimes$
$\frac{\mu_0}{2 \pi} \odot$
$\frac{\mu_0}{2 \pi} \otimes$
A hairpin like shape as shown in figure is made by bending a long current carrying wire. What is the magnitude of a magnetic field at point $P$ which lies on the centre of the semicircle ?
Figure shows a square loop $ABCD$ with edge length $a$. The resistance of the wire $ABC$ is $r$ and that of $ADC$ is $2r$. The value of magnetic field at the centre of the loop assuming uniform wire is
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
A thin wire of length $l$ is carrying a constant current. The wire is bent to form a circular coil. If radius of the coil, thus formed, is equal to $R$ and number of turns in it is equal to $n$, then which of the following graphs represent $(s)$ variation of magnetic field induction $(b)$ at centre of the coil
The magnetic field intensity at the point $O$ of a loop with current $i$, whose shape is illustrated below is