Extra exam question E4B06
Subelement E4, AMATEUR PRACTICES· Group E4B
How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?
- A.100 watts
- B.125 watts
- C.112.5 watts
- D.75 watts (correct answer)
WhyA directional power meter reading 100 watts forward and 25 watts reflected means the load is absorbing 75 watts. Power actually absorbed by the load equals forward power minus reflected power, since reflected power never reaches the load, it bounces back toward the source, so 100 watts forward minus 25 watts reflected leaves 75 watts absorbed, answer D. Adding the two figures, averaging them, or reporting the forward power alone would all overstate what the load actually receives.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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