The armature core of a DC generator is made from what material?

The armature core of a DC generator is constructed from soft iron or mild steel laminations because these materials possess the essential magnetic properties required for effective operation. Soft iron or mild steel offers high permeability, which allows magnetic lines of flux to pass through the core with minimal resistance, maximizing the efficiency of the magnetic circuit.

Additionally, using laminations—thin slices of the magnetic material insulated from each other—reduces eddy current losses significantly. Eddy currents can generate heat and decrease efficiency, so the lamination technique is critical in enhancing the performance of the generator. This construction helps ensure that the generator operates efficiently, delivering the maximum amount of electrical energy for a given mechanical input.

Other materials like plastic or composite materials lack the necessary magnetic properties and would not function effectively as part of the generator's magnetic circuit. Pure copper, while an excellent conductor of electricity, is not suitable for the armature core because it does not have the magnetic permeability required for effective magnetism in this application. Thus, the correct choice is the use of soft iron or mild steel laminations for the armature core.