Question

Two long straight parallel wires in vacuum are 4 m apart and carry currents of 2 A and 6 A in the same direction. Find the neutral point, i.e., the point at which the resultant magnetic induction is zero.

Answer 1

Data: I₁ =2 A, I₂= 6 A, a =4 m

The currents through the wires are in the same direction. Therefore, the two magnetic inductions \(\vec{B_1}\) and \(\vec{B_2}\) will have opposite directions at any point between the two wires. Hence, the point must lie between the two wires. For the resultant magnetic induction to be zero, we must have B₁ = B₂. Let the corresponding point (the neutral point) be at a distance a₁ from the first wire and a₂ from the second wire.

The neutral point lies at a distance of 1 m from the wire carrying a current of 2 A.