Question

Vaesd

Answer 1

to cancel out the electromagnetism. Any current will exhibits electromagnetism perpendicular to it's direction of propagation. Electromagnetism can be a hazardous thing do your health, so that's why they need to cancel it out somehow, and this is how it's possible...

Since the direction of electromagnetism is perpendicular, if you have two currents in the opposite direction, the direction of the two electromagnetic forces are also in the opposite direction, thus canceling each other out