Two parallel wires are carrying electric currents of equal magnitude and in the same direction. They exert

$A$ wire carrying a current $i$ is placed in a uniform magnetic field $B$ in the form of the curve $y = a \sin \left( \frac{\pi x}{L} \right)$,where $0 \leq x \leq 2L$. The magnetic force on the wire is

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:

$A$ square loop of length $L$ is placed with its edges parallel to the $XY$-axes. The loop carries a current $I$. If the magnetic field in the region varies as $B = B_0 \left(1 + \frac{xy}{L^2}\right) \hat{k}$, then the magnitude of the net force on the loop will be:

$A$ wire loop of irregular shape carrying current is placed in an external magnetic field. If the wire is flexible,the shape of the loop changes to

Three long,straight and parallel wires carrying currents are arranged as shown in the figure. The force experienced by $10\, cm$ length of wire $Q$ is