Two parallel conductors are carrying currents in the opposite direction.The currents are non-zero and not necessarily equal.The magnitude of the magnetic field midway between them is 40 mT.If one of the currents then has its direction reversed,what is the resulting magnitude of the magnetic field midway between them?

Question

Quizplus · Accepted Answer

The magnitude of the magnetic field midway between the conductors is given by B = μ₀*I/(2*d), where μ₀ is the permeability of free space, I is the current in the conductors, and d is the distance between the conductors. Since the currents in the conductors are in opposite directions, their magnetic fields add together at the midpoint, resulting in a net magnetic field of B = μ₀*(I1-I2)/(2*d). When the direction of one of the currents is reversed, the net magnetic field becomes B = μ₀*(I1+I2)/(2*d), which can be either greater or less than the initial value of 40 mT, depending on the magnitudes of the currents. However, since the question does not provide any information about the magnitudes of the currents, the only safe choice is C, a value less than 40 mT.

Two Parallel Conductors Are Carrying Currents in the Opposite Direction