General exam question G5B03
Subelement G5, ELECTRICAL PRINCIPLES· Group G5B
G5B03
How many watts of electrical power are consumed if 400 VDC is supplied to an 800-ohm load?
- A.0.5 watts
- B.200 watts (correct answer)
- C.400 watts
- D.3200 watts
Why400 VDC supplied to an 800-ohm load consumes 200 watts. Power dissipated by a resistive load can be found from P = V²/R, so 400 volts squared (160,000) divided by 800 ohms works out to 200 watts, answer B. The other values don't follow from that calculation with the given voltage and resistance.
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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