Does a Transformer Respond Only to DC? Evaluate the statement: “A transformer responds only to dc.”

Introduction / Context:
Transformers rely on changing magnetic flux to induce voltages. Understanding whether they work with AC or DC is foundational for correct application and preventing core saturation and overheating.

Given Data / Assumptions:

• Conventional iron or ferrite core transformer.
• Faraday’s law of electromagnetic induction applies.
• Steady DC is a constant (unchanging) signal.

Concept / Approach:

The induced voltage in a winding is proportional to the time rate of change of magnetic flux. DC does not change with time (di/dt = 0 after transients), so it does not sustain induction. AC, which changes with time, produces alternating flux that induces voltages in the coupled winding.

Step-by-Step Solution:

Verification / Alternative check:

Practical observation: connect a transformer primary to DC and you get a brief transient followed by no useful secondary voltage, often accompanied by excessive primary current and potential damage.

Why Other Options Are Wrong:

Any claim that transformers “respond only to DC” reverses the truth. Air gaps or autotransformer topology do not change the requirement for changing flux to induce voltage.

Common Pitfalls:

Confusing rectifiers (which convert AC to DC) with transformers, and assuming DC can be “stepped” with passive magnetic devices—it cannot without switching to create changing flux.

Final Answer:

False