A current in a conducting material which results from induction by moving or varying the magnetic field, causing energy loss in iron cores, is called what?

A current in a conducting material which results from induction by moving or varying the magnetic field, causing energy loss in iron cores, is called what?

• A. Hysteresis losses
• B. Capacitance currents
• C. Eddy currents
• D. Resistance

Answer: (C)

When a magnetic field around a conductor changes or the conductor moves through a magnetic field, an electric field is induced inside the material. This drives currents in closed loops within the conductor called eddy currents. In iron cores, these circulating currents flow through the metal and dissipate energy as heat because of the material’s resistance, leading to core heating and efficiency losses. The amount of eddy current depends on factors like the rate of change of the magnetic field, the size of the loops, and the metal’s conductivity; engineers reduce these losses by laminating the core or inserting insulation between layers to break up large loops and raise the effective resistance path. Hysteresis losses, by contrast, come from the lagging alignment of magnetic domains in ferromagnetic material during magnetization cycles, not from circulating currents. Capacitance currents aren’t the mechanism here, as this is about conduction within a metal. Resistance is the general opposition to current flow, not the specific circulating current phenomenon described.

When a magnetic field around a conductor changes or the conductor moves through a magnetic field, an electric field is induced inside the material. This drives currents in closed loops within the conductor called eddy currents. In iron cores, these circulating currents flow through the metal and dissipate energy as heat because of the material’s resistance, leading to core heating and efficiency losses. The amount of eddy current depends on factors like the rate of change of the magnetic field, the size of the loops, and the metal’s conductivity; engineers reduce these losses by laminating the core or inserting insulation between layers to break up large loops and raise the effective resistance path.

Hysteresis losses, by contrast, come from the lagging alignment of magnetic domains in ferromagnetic material during magnetization cycles, not from circulating currents. Capacitance currents aren’t the mechanism here, as this is about conduction within a metal. Resistance is the general opposition to current flow, not the specific circulating current phenomenon described.