Deep Dive: G5A02
The correct answer is B: Opposition to the flow of alternating current caused by capacitance or inductance. Reactance is opposition to the flow of alternating current caused by capacitance or inductance. Reactance is the AC equivalent of resistance, but it's frequency-dependent and caused by capacitors or inductors. For amateur radio operators, this is a fundamental circuit concept. Understanding this helps when working with AC circuits.
Why Other Answers Are Wrong
Option A: Incorrect. Reactance isn't opposition to DC caused by resistance - that's just resistance. Reactance is for AC, not DC. Option C: Incorrect. Reactance isn't reinforcement of DC flow - reactance opposes AC, it doesn't reinforce anything. Reinforcement isn't the concept. Option D: Incorrect. Reactance isn't reinforcement of AC flow - reactance opposes AC flow, it doesn't reinforce it. Opposition is the key concept.
Exam Tip
Reactance = opposition to AC caused by capacitance or inductance. Think 'R'eactance = 'R'esistance to 'A'C from 'C'apacitance/'I'nductance. Opposition to alternating current caused by capacitors or inductors. Not DC, not reinforcement - just AC opposition from C or L.
Memory Aid
Reactance = opposition to AC caused by capacitance or inductance. Think 'R'eactance = 'R'esistance to 'A'C. Opposition to alternating current caused by capacitors or inductors. Frequency-dependent opposition to AC.
Real-World Example
A capacitor or inductor in an AC circuit presents reactance - opposition to AC current flow. Unlike resistance (which opposes both AC and DC), reactance only opposes AC and is frequency-dependent. Capacitive reactance decreases with frequency, inductive reactance increases with frequency.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G5A
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 G5A topic.