The force per unit length on a straight wire carrying a current of $8 \ A$ making an angle of $30^{\circ}$ with a uniform magnetic field of $0.15 \ T$ is: (in $N \ m^{-1}$)

The force between two long parallel wires is $F$ when each one of them carries a certain current $I$. If the current in each is halved,the force between them would be . . . . . . .

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

The magnetic field existing in a region is given by $\vec B = B_0 [1 + \frac{x}{l}] \hat k$. $A$ square loop of edge $l$ carrying current $I_0$ is placed with its edges parallel to the $x-y$ axes. Find the magnitude of the net magnetic force experienced by the loop.

Three straight parallel current-carrying conductors are shown in the figure. The force experienced by the middle conductor of length $25\, cm$ is

Currents of $10 \ A$ and $2 \ A$ are passed through two parallel wires $A$ and $B$ respectively in opposite directions. If the wire $A$ is infinitely long and the length of the wire $B$ is $2 \ m$,the force acting on the conductor $B$,which is situated at a distance of $10 \ cm$ from $A$,will be . . . . . . .