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

$A$ thin uniform rod with negligible mass and length $l$ is attached to the floor by a frictionless hinge at point $P$. $A$ horizontal spring with force constant $k$ connects the other end to a wall. The rod is in a uniform magnetic field $B$ directed into the plane of the paper. What is the extension in the spring in equilibrium when a current $i$ is passed through the rod in the direction shown? Assume the spring is initially at its natural length.

$A$ square loop $ABCD$ carries a current $i$ and is placed near a long straight wire $XY$ carrying a current $I$ as shown in the figure. What is the net force on the loop?

The resultant force on the current loop $PQRS$ due to a long current-carrying conductor is:

Wires $1$ and $2$ carrying currents $i_1$ and $i_2$ respectively are inclined at an angle $\theta$ to each other. What is the force on a small element $dl$ of wire $2$ at a distance of $r$ from wire $1$ (as shown in figure) due to the magnetic field of wire $1$?

When current passing through two parallel wires flows in the same direction,the force between them is $......$,while when current passes in opposite directions through the same wires,the force between them is $......$ (attraction,repulsion).