$A$ $4.0 \ cm$ long straight wire carrying a current of $8 \ A$ is placed perpendicular to a uniform magnetic field of strength $0.15 \ T$. The magnetic force on the wire is . . . . . . $mN$.

$A$ conducting wire bent in the form of a parabola $y^2 = 2x$ carries a current $i = 2 \, A$ as shown in the figure. This wire is placed in a uniform magnetic field $\vec{B} = -4\,\hat{k} \, T$. The magnetic force on the wire is (in newton):

Two free parallel wires carrying currents in opposite directions:

$A$ square coil $ABCD$ of side $L$ is carrying a current $I_1$ in the clockwise direction. $A$ straight conductor carrying current $I_2$ (upward direction) is kept parallel to side $AB$ at a distance $\frac{L}{3}$ in the plane of $ABCD$. The net force on the coil $ABCD$ is ($\mu_0 =$ magnetic permeability).

$A$ thin flexible wire of length $L$ is connected to two adjacent fixed points and carries a current $I$ in the clockwise direction,as shown in the figure. When the system is put in a uniform magnetic field of strength $B$ going into the plane of the paper,the wire takes the shape of a circle. The tension in the wire is

Two very long,straight,parallel conductors $A$ and $B$ carry currents of $5\,A$ and $10\,A$ respectively and are at a distance of $10\,cm$ from each other. The direction of current in the two conductors is the same. The force acting per unit length between the two conductors is: $(\mu_0 = 4\pi \times 10^{-7} \text{ SI unit})$