What term describes induced circulating currents in a conducting material caused by a varying magnetic field?

• A. Eddy Current
• B. Hall Effect
• C. Flux Linkage
• D. Capacitance

Answer: (A)

Varying magnetic fields create an electromotive force around loops inside a conductor, causing charges to circulate. Those circulating currents within the material are called eddy currents. They flow in closed paths and tend to oppose the change in magnetic flux that produced them (Lenz’s law), which is why they heat the material as I^2R losses and can be a design consideration in magnetic cores and brakes. You’d minimize them with laminated or insulated conductors to disrupt large loops, or use materials with higher resistivity if needed.

The Hall effect is about a voltage that develops across a current-carrying conductor in a magnetic field due to sideways deflection of charge carriers, not circulating loops. Flux linkage is a measure of how much magnetic flux links with a circuit, not a current. Capacitance is the ability to store electric charge between conductors, unrelated to induced circulating currents from changing magnetic fields.