General exam question G6A05
Subelement G6, CIRCUIT COMPONENTS· Group G6A
G6A05
What is the approximate forward threshold voltage of a silicon junction diode?
- A.0.1 volt
- B.0.3 volts
- C.0.7 volts (correct answer)
- D.1.0 volts
WhyA silicon junction diode has an approximate forward threshold voltage of 0.7 volts. Silicon's bandgap sets its junction diode's forward conduction threshold at around 0.7 volt, the widely used rule-of-thumb figure for silicon diode drop, answer C. Germanium diodes need only a lower forward voltage, typically around 0.3 volt, to start conducting, and the other listed values don't match silicon's typical forward threshold.
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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