Deep Dive: G5B07
The correct answer is C: The RMS value. The value of an AC signal that produces the same power dissipation in a resistor as a DC voltage of the same value is the RMS value. RMS (Root Mean Square) voltage is the equivalent DC voltage that produces the same heating effect. For amateur radio operators, this is why RMS is used for power calculations. Understanding this helps when working with AC power.
Why Other Answers Are Wrong
Option A (Peak-to-peak value): Incorrect. Peak-to-peak value is too high - it's about 2.8 times RMS, so it would produce much more power. Peak-to-peak doesn't equal DC for power. Option B (Peak value): Incorrect. Peak value is too high - it's about 1.414 times RMS, so it would produce more power. Peak doesn't equal DC for power. Option D (Reciprocal of RMS): Incorrect. Reciprocal of RMS would be much smaller and produce less power. Reciprocal isn't the equivalent.
Exam Tip
AC equivalent to DC for power = RMS value. Think 'R'MS = 'R'eal 'M'easured 'S'trength (equivalent DC). RMS voltage produces same power dissipation as DC voltage of same value. Not peak-to-peak, not peak, not reciprocal - just RMS.
Memory Aid
AC equivalent to DC for power = RMS value. Think 'R'MS = 'R'eal 'M'easured 'S'trength. RMS voltage produces same power dissipation as DC voltage of same value. Standard for AC power calculations.
Real-World Example
120 volts RMS AC produces the same power in a resistor as 120 volts DC. The RMS value is the equivalent DC voltage for power calculations. Peak voltage (170V) would produce more power, but RMS (120V) equals DC (120V) for power dissipation.
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.