What is the core typically made of to reduce eddy currents?

What is the core typically made of to reduce eddy currents?

• A. Copper
• B. Aluminum
• C. Laminated Steel
• D. Solid Steel

Answer: (C)

Eddy currents are circulating currents that appear in conductive materials when the magnetic field around them changes. These currents waste energy as heat, so the core is made from thin sheets of metal, insulated from one another, to keep those loops small. This laminating drastically increases resistance to the currents and cuts losses, letting the core guide magnetic flux with minimum heat. The usual material is laminated soft magnetic steel (silicon steel) rather than a solid block. Copper or aluminum would conduct those currents more readily, and solid steel would allow larger eddy currents too, leading to more losses. Laminated steel provides the right balance of magnetic permeability and reduced eddy-current loss for efficient operation.

Eddy currents are circulating currents that appear in conductive materials when the magnetic field around them changes. These currents waste energy as heat, so the core is made from thin sheets of metal, insulated from one another, to keep those loops small. This laminating drastically increases resistance to the currents and cuts losses, letting the core guide magnetic flux with minimum heat. The usual material is laminated soft magnetic steel (silicon steel) rather than a solid block. Copper or aluminum would conduct those currents more readily, and solid steel would allow larger eddy currents too, leading to more losses. Laminated steel provides the right balance of magnetic permeability and reduced eddy-current loss for efficient operation.