What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?
The correct answer is A: Resonance. What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit is resonance. At resonance, reactances can have higher voltages than the source due to Q multiplication. For amateur radio operators, this is important for circuit theory. Understanding this helps when working with resonant circuits.
Exam Tip
Voltage across reactances higher than applied = resonance. Think 'R'esonance = 'R'eactance 'V'oltage 'E'nhancement. At resonance, reactances can have higher voltages than the source due to Q multiplication. Not capacitance, not low Q, not resistance - just resonance.
Memory Aid
"Voltage across reactances higher than applied = resonance. Think 'R'esonance = 'H'igher 'V'oltage. At resonance, reactances can have higher voltages than the source due to Q multiplication. Important for circuit theory."
Real-World Application
A series RLC circuit at resonance: The voltage across the reactances (inductor or capacitor) can be higher than the voltage applied to the entire circuit. This is due to the Q (quality factor) of the circuit - the reactance voltage is Q times the source voltage. This is what causes it - resonance.
Key Concepts
Why Other Options Are Wrong
Option B (Capacitance): Incorrect. Capacitance alone doesn't cause higher voltage - resonance does. Capacitance isn't the cause.
Option C (Low quality factor Q): Incorrect. Low Q doesn't cause higher voltage - resonance with high Q does. Low Q is wrong.
Option D (Resistance): Incorrect. Resistance doesn't cause higher voltage - resonance does. Resistance isn't the cause.
题目解析
The correct answer is A: Resonance. What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit is resonance. At resonance, reactances can have higher voltages than the source due to Q multiplication. For amateur radio operators, this is important for circuit theory. Understanding this helps when working with resonant circuits.
考试技巧
Voltage across reactances higher than applied = resonance. Think 'R'esonance = 'R'eactance 'V'oltage 'E'nhancement. At resonance, reactances can have higher voltages than the source due to Q multiplication. Not capacitance, not low Q, not resistance - just resonance.
记忆口诀
Voltage across reactances higher than applied = resonance. Think 'R'esonance = 'H'igher 'V'oltage. At resonance, reactances can have higher voltages than the source due to Q multiplication. Important for circuit theory.
实际应用示例
A series RLC circuit at resonance: The voltage across the reactances (inductor or capacitor) can be higher than the voltage applied to the entire circuit. This is due to the Q (quality factor) of the circuit - the reactance voltage is Q times the source voltage. This is what causes it - resonance.
错误选项分析
Option B (Capacitance): Incorrect. Capacitance alone doesn't cause higher voltage - resonance does. Capacitance isn't the cause. Option C (Low quality factor Q): Incorrect. Low Q doesn't cause higher voltage - resonance with high Q does. Low Q is wrong. Option D (Resistance): Incorrect. Resistance doesn't cause higher voltage - resonance does. Resistance isn't the cause.
知识点
Voltage across reactances, Series RLC circuit, Higher than applied voltage, Resonance
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.