Two long parallel wires are at a distance of $1$ metre. Both of them carry one ampere of current. The force of attraction per unit length between the two wires is
$1\,N/m$
$2 \times {10^{ - 7}}\,N/m$
$1 \times {10^{ - 2}}\,N/m$
$4\pi \times {10^{ - 7}}\,N/m$
$A, B$ and $C$ are parallel conductors of equal length carrying currents $I, I$ and $2I$ respectively. Distance between $A$ and $B$ is $x$. Distance between $B$ and $C$ is also $x$. ${F_1}$ is the force exerted by $B$ on $A$ and $F_2$ is the force exerted by $B$ on $A$ choose the correct answer
Two parallel conductors $A$ and $B$ of equal lengths carry currents $I$ and $10\, I$, respectively, in the same direction. Then
Two free parallel wires carrying currents in opposite direction
There long straight wires $A$, $B$ and $C$ are carrying current as shown figure. Then the resultant force on $B$ is directed .....
Assertion : Free electrons always keep on moving in a conductor even then no magnetic force act on them in magnetic field unless a current is passed through it.
Reason : The average velocity of free electron is zero.