Three long current-carrying wires $P, Q,$ and $R$ are placed perpendicular to the plane of the paper as shown. The magnetic force per unit length on wire $R$ is:

Three long straight wires are carrying current as shown in the diagram. The magnetic force per unit length on wire $Q$ is $..... \times 10^{-7} \ N/m$.

As shown in the figure, a metallic rod of linear density $0.45\,kg\,m^{-1}$ is lying horizontally on a smooth inclined plane which makes an angle of $45^{\circ}$ with the horizontal. The minimum current flowing in the rod required to keep it stationary, when a $0.15\,T$ magnetic field is acting on it in the vertical upward direction, will be $....A$ $\{$Use $g=10\,m/s^2\}$

$A$ current of $1 \ A$ is flowing along the positive $x$-axis through a straight wire of length $0.5 \ m$ placed in a region of a magnetic field given by $\vec{B} = (2\hat{i} + 4\hat{j}) \ T$. The magnitude and the direction of the force experienced by the wire are, respectively:

Two long and parallel straight wires $A$ and $B$ carrying currents of $10 \ A$ and $4 \ A$ in the same direction are separated by a distance of $2 \ cm$. Estimate the force on a $4 \ cm$ section of wire $A$. ( $\mu_0 = 4 \pi \times 10^{-7} \ SI$ ).

$A$ long straight wire is carrying current $I_1$ in the $+z$ direction. The $x-y$ plane contains a closed circular loop carrying current $I_2$ and does not encircle the straight wire. The net force on the loop will be: