Two parallel wires carrying currents in the same direction
- A. attract each other
- B. repel each other
- C. exert no force on each other
- D. twist about one another
Explanation
Each wire sits in the field of the other, and applying the left hand rule shows the forces to be inward when the currents are parallel, outward when they are antiparallel. So like currents attract, which is the opposite of the behaviour of like charges. This force is what defines the ampere.
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