Two long parallel wires are at a distance of $1 \ m$. Both of them carry $1 \ A$ of current. The force of attraction per unit length between the two wires is

$A$ 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

$A$ rigid square loop of side $a$ carrying current $I_2$ is lying on a horizontal surface near a long wire carrying current $I_1$ in the same plane as shown in the figure. The net force on the loop due to the wire will be:

$A$ long wire $A$ carries a current of $10 \, A$. Another long wire $B$,which is parallel to $A$ and separated by $0.1 \, m$ from $A$,carries a current of $5 \, A$ in the opposite direction to that in $A$. What is the magnitude and nature of the force experienced per unit length of $B$ $(\mu_0 = 4\pi \times 10^{-7} \, T \cdot m/A)$?

As shown in the figure, a uniform straight wire of length $30 \sqrt{3} \text{ cm}$ is bent in the form of an equilateral triangle $ABC$. $A$ uniform magnetic field $2 \text{ T}$ is applied parallel to the side $BC$. If the current through the wire is $2 \text{ A}$, the magnitude of the force on the side $AC$ is ($\overline{B}$ represents the direction of the magnetic field).

$ABCD$ is a rectangular loop made of uniform wire. If $AD = BC = 2 \text{ cm}$,what is the magnetic force per unit length acting on wire $DC$ due to wire $AB$ if the ammeter reads $20 \text{ A}$? (The lengths of $AB$ and $DC$ are large in comparison with the other two sides).