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After the switching transient, what does steady DC on a transformer's primary produce at its secondary?

No sustained secondary voltage, because the magnetic field is no longer changing.

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  1. A normal stepped DC voltage
  2. No sustained output voltage ✔
  3. A continuous AC voltage

Why: Switching DC on can create a brief pulse while magnetic flux changes. Once the current and flux are steady, no secondary voltage is induced, and the primary winding may overheat.

Huh, didn't know that: Opening and closing a DC switch can create brief voltage pulses at the secondary.

The dad joke
I tried to power my transformer with DC. It just would not change.
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References

Answer: No sustained output voltage. Switching DC on can create a brief pulse while magnetic flux changes. Once the current and flux are steady, no secondary voltage is induced, and the primary winding may overheat.

  1. OpenStax College Physics 2e, 23.7 Transformers openstax.org/books/college-physics-2e/pages/23-7-transformers
    If there is no change in primary voltage, there is no voltage induced in the secondary.
    Checked 2026-10-10.

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