Question

A current‑carrying wire lies in a region where there is an external magnetic field, but there is no magnetic force acting on the wire. How can this be? The wire itself is moving in the direction of the magnetic field at just the right speed. The magnetic field is generated by a second wire carrying a current in the opposite direction. The wire is a circular loop whose plane is oriented parallel to the magnetic field. The current is carried by equal numbers of positive and negative charges that flow in opposite directions along the wire. The length of the wire is oriented either parallel or antiparallel to the magnetic field lines at the location of the wire.

Answer 1

Answer:

The length of the wire is oriented either parallel or antiparallel to the magnetic field lines at the location of the wire.

Explanation:

As we know that the magnetic force on current carrying wire is given as

$F = i(\vec L \times \vec B)$

now we know that

i = current flowing in the wire

L = length vector of the wire which is along the current flowing in the wire

B = magnetic field strength

now we know that

$F = iLB sin\theta = 0$

so here if the force is zero then either

$\theta = 0 degree$ OR $\theta = 180 degree$

so correct answer will be

The length of the wire is oriented either parallel or antiparallel to the magnetic field lines at the location of the wire.