General exam question G0B10
Subelement G0, ELECTRICAL AND RF SAFETY· Group G0B
Which of the following is a danger from lead-tin solder?
- A.Lead can contaminate food if hands are not washed carefully after handling the solder (correct answer)
- B.High voltages can cause lead-tin solder to disintegrate suddenly
- C.Tin in the solder can “cold flow,” causing shorts in the circuit
- D.RF energy can convert the lead into a poisonous gas
WhyA danger from lead-tin solder is that lead can contaminate food if hands are not washed carefully after handling the solder. Lead-tin solder contains lead, a toxic metal, and residue left on the hands after handling it can end up ingested if food is handled without washing up first, so that's the real everyday hazard, answer A. Solder doesn't "disintegrate" under high voltage, tin cold-flow isn't the danger being asked about here, and RF energy doesn't convert lead into a poisonous gas, 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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