Deep Dive: T5A11
The correct answer is D: All these choices are correct. All types of current flow - direct current (DC), alternating current (AC), and RF current - are opposed by resistance. Resistance opposes the flow of any type of current, regardless of whether it's DC, AC, or RF. Resistance is a fundamental property that opposes current flow. It doesn't matter if the current is DC (flowing in one direction), AC (alternating direction), or RF (high-frequency alternating current) - resistance opposes all of them. The opposition might be measured differently (DC resistance vs. AC impedance), but resistance itself opposes current flow in all cases. This is why conductors with low resistance are used for all types of electrical circuits.
Why Other Answers Are Wrong
This question has no incorrect options since all choices are correct. However, it's important to understand that resistance opposes all types of current flow - DC, AC, and RF.
Exam Tip
Resistance opposes all current types. Remember: Resistance opposes direct current, alternating current, and RF current. All current flow is opposed by resistance.
Memory Aid
**R**esistance **O**pposes **A**ll **C**urrent (think 'RO = AC' = Resistance Opposes All Current, DC/AC/RF)
Real-World Example
A resistor in a circuit opposes current flow whether you're using DC power (like from a battery), AC power (like from household outlet), or RF signals (like in a transmitter). The resistance value might be the same for DC, but for AC and RF, you also consider reactance (forming impedance), but resistance still opposes the current flow in all cases.
Source & Coverage
Question Pool: 2022-2026 Question Pool
Subelement: T5A
Reference: FCC Part 97.3
Key Concepts
Verified Content
Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T5A topic.