Question

A very long. straight wire carries a current of 0.21 A. This wire is tangent to a single-turn, circular wire loop that also carries a current. The directions of the currents are such that the net magnetic field at the center of the loop is zero. Both wires are insulated and have diameters that can be neglected. How much current is there in the loop?

Answer 1

The current in the loop is 0.21 A.

Step-by-step explanation:

The current in the loop can be found by applying Ampere's Law, which states that the magnetic field around a closed loop is equal to the permeability of free space multiplied by the current passing through the loop.

Since the net magnetic field at the center of the loop is zero, the magnetic field created by the long straight wire must be equal and opposite to the magnetic field created by the loop. This means that the current in the loop must have the same magnitude, but opposite direction, as the current in the straight wire.

Therefore, the current in the loop is 0.21 A.