General exam question G5C04
Subelement G5, ELECTRICAL PRINCIPLES· Group G5C
G5C04
What is the approximate total resistance of a 100- and a 200-ohm resistor in parallel?
- A.300 ohms
- B.150 ohms
- C.75 ohms
- D.67 ohms (correct answer)
WhyA 100-ohm and a 200-ohm resistor in parallel have an approximate total resistance of 67 ohms. Two resistors in parallel combine as (R1 × R2) ÷ (R1 + R2), so 100 times 200 (20,000) divided by 300 comes out to about 67 ohms, answer D. The other values don't follow from applying that two-resistor parallel formula to 100 and 200 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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