What type of current flow is opposed by resistance?
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.
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 Application
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.
FCC Part 97.3Key Concepts
Why Other Options 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.
题目解析
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.
考试技巧
Resistance opposes all current types. Remember: Resistance opposes direct current, alternating current, and RF current. All current flow is opposed by resistance.
记忆口诀
**R**esistance **O**pposes **A**ll **C**urrent (think 'RO = AC' = Resistance Opposes All Current, DC/AC/RF)
实际应用示例
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.
错误选项分析
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.
知识点
Resistance, DC, AC, RF current
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.