Two thin long parallel wires separated by a distance $b$ are carrying a current $i$ $A$ each. The magnitude of the force per unit length exerted by one wire on the other is

Two long straight wires are arranged parallel to each other and are kept $20$ cm apart in vacuum. They carry currents of $2$ $A$ and $4$ $A$ respectively in the same direction. What will be the magnetic force on a length of $10$ cm of either wire? $(\mu_0 = 4\pi \times 10^{-7} \text{ SI units})$

$A$ current loop $ABCD$ is held fixed on the plane of the paper as shown in the figure. The arcs $BC$ (radius $= b$) and $DA$ (radius $= a$) of the loop are joined by two straight wires $AB$ and $CD$. $A$ steady current $I$ is flowing in the loop. The angle made by $AB$ and $CD$ at the origin $O$ is $30^o$. Another straight thin wire with a steady current $I_1$ flowing out of the plane of the paper is kept at the origin. Due to the presence of the current $I_1$ at the origin:

$A$ metal ring of radius $r = 0.5 \, m$ with its plane normal to a uniform magnetic field $B$ of induction $0.2 \, T$ carries a current $I = 100 \, A$. The tension in newtons developed in the ring is:

$A$ conducting wire bent in the form of a parabola $y^2=2x$ carries a current of $4 \ A$ as shown in the figure. This wire is placed in a uniform magnetic field of induction $\vec{B}=+6 \hat{k} \ T$. The magnetic force on the wire is

$A$ current of $10 \text{ A}$ flows through a horizontal straight wire $A$ with both ends rigidly fixed. Wire $B$ is placed directly above and parallel to $A$. The weight per unit length of wire $B$ is $40 \times 10^{-3} \text{ N/m}$ and it carries a current of $20 \text{ A}$. Find the distance of wire $B$ from wire $A$ so that wire $B$ remains at rest. Also,state the direction of current flowing through it.