Question

Consider two parallel current carrying conductors separated by a distance. Which one of the following statements is true?

• A. Currents flowing in same direction will lead to repulsion
• B. Currents flowing in opposite directions will lead to attraction
• C. The conductors will always attract each other
• D. The conductors will always repel each other
• E. Currents flowing in same direction will lead to attraction and opposite directions will lead to repulsion

Hint:

Think of it as the "Magnetism Opposite" rule: Unlike electrostatic charges (which attract), anti-parallel currents repel; while like electrostatic charges (which repel), parallel currents attract.

Answer 1

Answer: (E)

Concept: Parallel conductors exert magnetic forces on one another. The magnetic field of the first conductor interacts with the moving charges in the second conductor, creating a force defined by the Lorentz force and Fleming's Left-Hand Rule.

Step 1: {Analyze the case of parallel currents.}
When currents flow in the same direction, the magnetic fields between the wires are in opposite directions, resulting in an attractive magnetic force that pulls the conductors toward each other.

Step 2: {Analyze the case of anti-parallel currents.}
When currents flow in opposite directions, the magnetic fields between the wires reinforce each other, creating a repulsive magnetic force that pushes the conductors apart.

Step 3: {Match findings with the given statements.}
Based on the physical interaction:
• Same direction: Attraction
• Opposite direction: Repulsion This observation corresponds exactly to statement (E).