General exam question G5C06
Subelement G5, ELECTRICAL PRINCIPLES· Group G5C
What is the voltage output of a transformer with a 500-turn primary and a 1500-turn secondary when 120 VAC is applied to the primary?
- A.360 volts (correct answer)
- B.120 volts
- C.40 volts
- D.25.5 volts
WhyA transformer with a 500-turn primary and a 1500-turn secondary produces 360 volts output when 120 VAC is applied to the primary. A transformer's output voltage scales with its turns ratio, secondary turns divided by primary turns, so 1,500 secondary turns over 500 primary turns is a ratio of 3, and 120 VAC times 3 comes out to 360 volts, answer A. The other values don't follow from applying that turns-ratio relationship to a 500:1500 winding with 120 VAC in.
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.
Related questions
- G5C01What causes a voltage to appear across the secondary winding of a transformer when an AC voltage source is connected across its primary winding?
- G5C02What 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?
- G5C03What is the total resistance of a 10-, a 20-, and a 50-ohm resistor connected in parallel?
- G5C04What is the approximate total resistance of a 100- and a 200-ohm resistor in parallel?
- G5C05Why is the primary winding wire of a voltage step-up transformer usually a larger size than that of the secondary winding?