Transformer loading: does the secondary current primarily depend on the secondary voltage and the connected load resistance (I2 ≈ V2 / Rload in steady state)?

Introduction / Context:
In practical transformer applications, the secondary current is set by the load connected to the secondary and the secondary voltage delivered by the turns ratio. Understanding this relationship underpins power supply sizing, regulation expectations, and thermal design.

Given Data / Assumptions:

• Ideal transformer approximation: V2 = (N2/N1) * V1.
• Sinusoidal steady-state operation.
• Load modeled as a resistance Rload (no significant reactance).
• Negligible winding resistance and leakage for first-order reasoning.

Concept / Approach:
With an ideal source, the secondary presents a Thevenin-like supply of magnitude V2. The current through a resistive load is I2 = V2 / Rload. The primary current adjusts automatically (by reflected impedance) to support the delivered secondary power, with I1 ≈ (N2/N1) * I2 for an ideal device, neglecting magnetizing component.

Step-by-Step Solution:

Verification / Alternative check:
Replace the secondary and load by their primary-reflected equivalents; the same current results after transforming back, confirming consistency.

Why Other Options Are Wrong:
Incorrect: contradicts Ohm’s law at the secondary terminals.
Only true for autotransformers or saturated cores: both claims are unrelated to the linear, ideal behavior described.

Common Pitfalls:
Confusing magnetizing current (small and mostly reactive) with load current; assuming secondary current is “fixed by the transformer” rather than by the load.

Final Answer:
Correct