Adjoining figure shows a very long semicylindrical conducting shell of radius $R$ and carrying a current $i$. An infinitely long straight current carrying conductor is lying along the axis of the semi-cylinder. If the current flowing through the straight wire be $i_0$, then the force per unit length on the conducting wire is
$\frac{{{\mu _0}i{i_0}}}{{{\pi ^2}R}}$
$\frac{{{\mu _0}i{i_0}}}{{\pi {R^2}}}$
$\frac{{{\mu _0}i_0^2i}}{{{\pi ^2}R}}$
none of these
A conducting circular loop of radius $r$ carries a constant current $i$. It is placed in a uniform magnetic field $\overrightarrow B $, such that $\overrightarrow B $ is perpendicular to the plane of the loop. The magnetic force acting on the loop is
Write formula for moving charge $\mathrm{q}$ in magnetic field.
A square shaped wire loop of mass $m$, resistance $R$ and side $a$ moving speed $v_{0}$, parallel to the $X$-axis, enters a region of uniform magnetic field $B$, which is perpendicular to the plane of the loop. The speed of the loop changes with distance $x(x < a)$ in the field, as
Two thin long parallel wires separated by a distance $b$ are carrying a current $i$ $amp$ each. The magnitude of the force per unit length exerted by one wire on the other is
Two long parallel copper wires carry currents of $5\,A$ each in opposite directions. If the wires are separated by a distance of $0.5\,m$, then the force between the two wires is