Deep Dive: G5B06
The correct answer is B: 100 watts. The PEP produced by 200 volts peak-to-peak across a 50-ohm dummy load is 100 watts. Peak voltage = peak-to-peak/2 = 200/2 = 100V. PEP = Vpeak²/R = 100²/50 = 10,000/50 = 200W... Wait, let me recalculate: Vpeak = Vpp/2 = 200/2 = 100V. Power = Vpeak²/(2R) for PEP, or Vrms²/R where Vrms = Vpeak/√2 = 100/1.414 = 70.7V. P = 70.7²/50 = 5,000/50 = 100W. For amateur radio operators, this is a basic PEP calculation.
Why Other Answers Are Wrong
Option A (1.4 watts): Incorrect. 1.4 watts is way too low - calculation error. 200V peak-to-peak gives much more power. Option C (353.5 watts): Incorrect. 353.5 watts is too high - that might be using peak voltage incorrectly. Correct calculation gives 100W. Option D (400 watts): Incorrect. 400 watts is too high - that might be using peak-to-peak voltage directly. Correct calculation gives 100W.
Exam Tip
PEP from 200V peak-to-peak, 50Ω: Vpeak = Vpp/2 = 100V, Vrms = Vpeak/√2 = 70.7V, P = Vrms²/R = 70.7²/50 = 100W. Think 'P'EP = 'P'eak 'E'nvelope 'P'ower. Convert peak-to-peak to RMS, then use P = Vrms²/R. Not 1.4W, not 353.5W, not 400W - just 100W.
Memory Aid
PEP from 200V peak-to-peak, 50Ω = 100W. Think 'P'EP = 'P'eak 'E'nvelope 'P'ower. Vpeak = Vpp/2 = 100V, Vrms = 70.7V, P = 100W. Standard PEP calculation.
Real-World Example
200 volts peak-to-peak across a 50-ohm load. Peak voltage = 200/2 = 100V. RMS voltage = 100/√2 = 70.7V. PEP = Vrms²/R = 70.7²/50 = 5,000/50 = 100 watts. This is the PEP produced.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G5B
Reference: 2023-2027 Question Pool · G5 - Electrical Principles
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G5B topic.