General exam question G5C02
Subelement G5, ELECTRICAL PRINCIPLES· Group G5C
What is the output voltage if an input signal is applied to the secondary winding of a 4:1 voltage step-down transformer instead of the primary winding?
- A.The input voltage is multiplied by 4 (correct answer)
- B.The input voltage is divided by 4
- C.Additional resistance must be added in series with the primary to prevent overload
- D.Additional resistance must be added in parallel with the secondary to prevent overload
WhyApplying an input signal to the secondary winding of a 4:1 voltage step-down transformer, instead of the primary, multiplies that input voltage by 4 at the output. A transformer's turns ratio works the same in either direction, so feeding a signal into what's normally the secondary (low-voltage) winding of a 4:1 step-down transformer makes it behave as a 1:4 step-up, multiplying that input voltage by 4 at the other winding, answer A. It doesn't divide the voltage by 4 (that's what would happen feeding the primary as usual), and no added series or parallel resistance is needed just to reverse which winding is driven, so B, C, and D are wrong.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2023-2027 NCVEC Element 3 pool (public domain); the explanation above is original writing, see our methodology.
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