Question

Two wires carrying equal currents i each, are placed perpendicular to each other, just avoiding a contact. If one wire is held fixed and the other is free to move under magnetic forces, what kind of motion will result?

Answer 1

The free wire will become parallel to the immovable wire so as to involve highest attractive force.

Explanation:

• On a wire, the magnetic force resounding an electric current i is F→=i.(l→×B→)F→=i.(l→×B→), where B is the magnetic field acting on the wire and l is the wire’s length.
• Supposing, there is one wire in the fixed horizontal direction and other wire is free to move in the vertical direction.
• Assume that the horizontal wire is traversing current to left from right and is held immovable perpendicular to the vertical wire, the free wire’s upper portion will incline to travel in the left direction.
• The wire’s lower portion will incline to move in the right direction, which is according to Fleming's left-hand rule.
• On the wire, the acting magnetic field is due to the fixed wire that will point into the paper plane overhead the wire and move out of the paper under the horizontal wire.
• The current will move in the free wire’s upward direction. So, the free wire will incline to become analogous to the fixed wire so as to involve greater attractive force.