In a transformer, the primary coil's input current is related to which factor?

The input current in the primary coil of a transformer is indeed directly related to the applied voltage to that coil. According to Ohm's Law, current is determined by the voltage applied and the resistance in the circuit. In a transformer, when you apply a certain voltage to the primary coil, the resulting current flowing through that coil is proportional to this voltage, assuming a relatively constant impedance.

If the voltage increases, the current in the primary coil will also increase, provided other factors, such as the total resistance of the circuit, remain constant. This relationship is crucial in designing transformers, as engineers must consider the primary voltage when determining the ratings and specifications for both the primary and secondary coils.

The number of turns in the secondary coil influences the voltage and current transformation between the primary and secondary windings, but it does not directly affect the primary input current. Similarly, while total resistance in the circuit and frequency of the supplied voltage can impact the behavior of the transformer and its efficiency, the fundamental relationship of the primary input current is mainly driven by the voltage applied to it.