Two parallel wires in free space are $10\, cm$ apart and each carries a current of $10\, A$ in the same direction. The force one wire exerts on the other per metre of length is

An infinitely long,straight conductor $AB$ is fixed and a current $i_1$ is passed through it. Another movable straight wire $CD$ of finite length carrying current $i_2$ is held perpendicular to it and released. Neglect the weight of the wire.

An infinitely long current-carrying wire and a small current-carrying loop are in the plane of the paper as shown. The radius of the loop is $a$ and the distance of its centre from the wire is $d$ $(d >> a)$. If the loop applies a force $F$ on the wire,then:

Three parallel wires $a$, $b$, and $c$ carrying currents $i_a$, $i_b$, and $i_c$ as shown in the figure are placed next to each other. The magnitude of the force on a length $l$ of the wire $a$, if $d_2 = 2 d_1$, $i_b = i_a$, and $i_c = 4 i_a$ is:

Give the expression for the force on a current-carrying conductor in a magnetic field.

$A$ thin flexible wire of length $L$ is connected to two adjacent fixed points and carries a current $I$ in the clockwise direction,as shown in the figure. When the system is put in a uniform magnetic field of strength $B$ going into the plane of the paper,the wire takes the shape of a circle. The tension in the wire is