The __________ is made of thin laminations of grain-oriented silicon steel rolled into layers, with each side coated with an insulation material.

• A. Core
• B. Winding
• C. Tank
• D. Insulating Fluid

Answer: (A)

At the heart of this concept is the magnetic path in a transformer, built from thin laminations of grain-oriented silicon steel that are stacked together. Each sheet is coated with insulation to prevent currents from crossing between layers. This laminated, insulated structure reduces eddy current losses and takes advantage of the steel’s favorable magnetic properties in the rolling direction, which improves efficiency at AC frequencies. If a solid block were used, changing magnetic fields would drive large circulating currents, wasting energy as heat. The winding and the tank are separate parts of the transformer, and insulating fluid may be used for cooling and insulation but does not form the magnetic path.