General exam question G5C03
Subelement G5, ELECTRICAL PRINCIPLES· Group G5C
G5C03
What is the total resistance of a 10-, a 20-, and a 50-ohm resistor connected in parallel?
- A.5.9 ohms (correct answer)
- B.0.17 ohms
- C.17 ohms
- D.80 ohms
WhyA 10-, a 20-, and a 50-ohm resistor connected in parallel have a total resistance of about 5.9 ohms. For resistors in parallel, the reciprocal of total resistance equals the sum of the reciprocals of each resistor, so 1/10 + 1/20 + 1/50 (0.1 + 0.05 + 0.02 = 0.17) inverted gives about 5.9 ohms, answer A. The other values don't follow from applying the parallel-resistance formula to 10, 20, and 50 ohms.
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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