Technician exam question T4A01
Subelement T4, AMATEUR RADIO PRACTICES· Group T4A
Which of the following is an appropriate power supply rating for a typical 50-watt output mobile FM transceiver?
- A.24.0 volts at 4 amperes
- B.13.8 volts at 4 amperes
- C.24.0 volts at 12 amperes
- D.13.8 volts at 12 amperes (correct answer)
Why13.8 volts at 12 amperes is an appropriate power supply rating for a typical 50-watt output mobile FM transceiver. A 50-watt mobile FM transceiver runs off the vehicle's nominal 13.8-volt electrical system (the charging voltage of a 12-volt lead-acid battery), and producing 50 watts of RF at that voltage typically draws on the order of 10 to 12 amperes, so a supply rated 13.8 volts at 12 amperes is the right match, answer D. The 24-volt options (A, C) are the wrong voltage entirely for automotive gear, and B's 4 amperes is far too little current for a 50-watt radio.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2026-2030 NCVEC Element 2 pool (public domain); the explanation above is original writing, see our methodology.
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