$A$ semicircular ring of radius $R$ carrying current $i$ is placed in a uniform magnetic field of intensity $B$ such that the plane of the wire is perpendicular to the magnetic field,as shown in the figure. The net force acting on the ring is

$A$ wire carrying a steady current $I$ is kept in the $x$-$y$ plane along the curve $y=A \sin \left(\frac{2 \pi}{\lambda} x\right)$. $A$ magnetic field $B$ exists in the $z$-direction. The magnitude of the magnetic force on the portion of the wire between $x=0$ and $x=\lambda$ is

What is the magnitude of magnetic force per unit length (in $N \;m^{-1}$) on a wire carrying a current of $8 \;A$ and making an angle of $30^{\circ}$ with the direction of a uniform magnetic field of $0.15 \;T$?

$A$ rectangular coil $ABCD$ is hung from one side of a balance as shown in the figure. $A$ $500 \, g$ mass is added to the other arm to balance the weight of the coil. $A$ current of $9.8 \, A$ is passed through the coil and a constant magnetic field of $0.4 \, T$ acting inward is switched on such that only arm $CD$ of length $1.5 \, cm$ lies in the field. The additional mass $m$ that must be added to regain the balance is: (in $, g$)

$A$ wire $AB$ is carrying a steady current $I_1$ and is kept on a table. Another wire $CD$ carrying current $I_2$ is held directly above it at a distance $r$. When the wire $CD$ is left free and it remains suspended at its position, find its mass per unit length. (Given: $g$ = acceleration due to gravity, $\mu_0$ = permeability of free space)

If a straight current-carrying wire of linear density $0.12 \ kg \ m^{-1}$ is suspended in mid-air by a uniform horizontal magnetic field of $0.5 \ T$ normal to the length of the wire,then the current through the wire is (Acceleration due to gravity $= 10 \ m \ s^{-2}$; Neglect earth's magnetic field) (in $A$)