Two long straight wires $A$ and $B$ carrying equal current $I$ were kept parallel to each other at distance $d$ apart. The magnitude of the magnetic force experienced by length $L$ of wire $A$ is $F$. If the distance between the wires is halved and the currents are doubled,the force $F_2$ on length $L$ of wire $A$ will be:

What is the magnitude of magnetic force per unit length 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 $0.15\,T$? (in $N\,m^{-1}$)

Two free parallel wires carrying currents in opposite directions:

$A$ magnetic field is in the $+Y$ direction. $A$ current $i$ flows through the wire $PQRSTU$. Each side has a length $L$. What is the net force on the wire?

Two thin,long,parallel wires,separated by a distance $d$,carry a current of $i$ in the same direction. They will

$A$ massless square loop of wire of resistance $R$ supporting a mass $M$ hangs vertically with one of its sides in a uniform magnetic field $B$ directed outwards in the shaded region. $A$ d.c. voltage $V$ is applied to the loop. For what value of $V$ will the magnetic force exactly balance the weight of the supporting mass $M$? (side of loop $= L, g =$ acceleration due to gravity)