Question

What is the magnetic field midway between two parallel conductors carrying sameamount of current in the same direction and in the opposite direction?

Answer 1

In the same direction the answer is zero.

(use the cockscrew rule)

The magnetic field due to both conductors cancel out.

When then current directions in both conductors are on opposite directions

then the magnetic field will add up.

Answer 2

Explanation:

The direction of magnetic field is given by the right hand thumb rule.

The force is attractive if the current is in the opposite directions, and if they are in the same direction it is repulsive. This power is responsible in electrical arcs and plasmas for the pinch effect. Whether or not the currents are in cables, force exists.

Thus, by the right hand rule, a current in a field up out of the page gives a force to the left. Two parallel wires bearing the same currents draw each other; wires with currents in opposite directions repel each other.