Question

When infinitely long parallel wires carry equal currents in the same direction, the magnetic field at the midpoint in between the two wires is zero.

(a) True

(b) False

I had been asked this question in an interview for internship.

This question is from Ampere and Forces between Two Parallel Currents in section Moving Charges and Magnetism of Physics – Class 12

Answer 1

The correct option is (a) True

For explanation I would say: Yes, when infinitely long parallel wires carry equal currents in the same direction, the magnetic field at the midpoint in between the two wires is zero. This is because, when the wires carry equal currents in the same direction, the magnetic field created at the midpoint will cancel out each other and thus, the field is zero.