What is true about the power ratings of the primary and secondary windings of a transformer?

The power capacity of both windings of a transformer is always equal due to the principle of conservation of energy in the ideal transformer model. This means that the input power to the primary winding must equal the output power from the secondary winding, assuming there are no losses. In mathematical terms, if the primary winding receives a certain amount of power (measured in watts), the secondary winding will deliver an equal amount of power (again, measured in watts), adjusted for voltage and current changes according to the turns ratio of the windings.

This relationship holds true under ideal conditions where there are no losses due to heat, magnetic hysteresis, or other inefficiencies. Therefore, it is a fundamental characteristic of transformer operation that the power capacity of both windings remains equal, which is critical for ensuring that the energy is effectively transferred from the primary to the secondary side.

The other options suggest variations in power capacity or unequal performance between the windings, which do not align with the principles of how transformers are designed to function. While real transformers may exhibit some losses and the actual power can differ slightly due to inefficiencies, the core principle remains that in an ideal transformer, the power rating of both windings is equal.