What is the magnitude of magnetic force per unit length on a wire carrying a current of $8\,A$ and making an angle of $30^o$ with the direction of a uniform magnetic field of $0.15\, T$ ?.....$Nm^{-1}$
$0.4$
$0.6 $
$4 $
$6$
A semi circular arc of radius $r$ and a straight wire along the diameter, both are carrying same current $i.$ Find out magnetic force per unit length on the small element $P$, which is at the centre of curvature.
An infinitely long current carrying wire and a small current carrying loop are in the plane of the paper as shown. the radius of the loop is $a$ and distance of its centre from the wire is $d (d >> a)$. If the loop applies a force $F$ on the wire then
A straight wire $AB$ of mass $40\,g$ and length $50\,cm$ is suspended by a pair of flexible leads in uniform magnetic field of magnitude $0.40\,T$ as shown in the figure. The magnitude of the current required in the wire to remove the tension in the supporting leads is ...........$A$. (Take $g=10\,ms ^{-2}$ ).
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
An elastic circular wire of length $l$ carries a current $I$. It is placed in a uniform magnetic field $\mathop B\limits^ \to $ (Out of paper) such that its plane is perpendicular to the direction of $\mathop B\limits^ \to $. The wire will experience