This option suggests that the two coils of a transformer are wound on the same iron core. Iron cores are commonly used in transformers for their magnetic properties.
A copper core is not typically used as the core of a transformer. Copper is a good conductor of electricity but does not possess the magnetic properties needed for a transformer core.
Gold is a good conductor of electricity, but it is not commonly used as the core material in transformers due to its high cost and lack of ideal magnetic properties.
Steel cores are commonly used in transformers along with iron cores due to their magnetic properties. Steel is a good magnetic material and provides the necessary support and magnetic characteristics for transformer operation.
The correct statement is A. Iron core. In principle, transformers consist of two coils of copper wire wound on the same iron core. The iron core enhances the magnetic coupling between the coils, allowing for efficient energy transfer in the transformer.