Where is the neutral point between 2 wires

1. Nov 22, 2004

bchl85

There are 2 long wires A and B, placed 10cm apart. The currents in 2 wires are the same, 0.3A downwards. Where is the neutral point, how far is it from wire A?

2. Nov 22, 2004

vsage

If the two wires have the same current in the same direction then the neutral point should be dead center because the magnetic field at a radius r from both wires would be the same. Assuming the two wires are placed flat on a page going up and down and the current is moving up (A being to the left of B), the field from B is moving out of the page 5cm from the wire and the field from A is moving into the page 5cm from that wire. Long answer for a short question.