What is the relationship between the AC current through an inductor and the voltage across an inductor?
The correct answer is A: Voltage leads current by 90 degrees. What is the relationship between the AC current through an inductor and the voltage across an inductor is that voltage leads current by 90 degrees. In an inductor, voltage leads current by 90°. For amateur radio operators, this is important for circuit theory. Understanding this helps when working with inductors.
Exam Tip
Inductor AC relationship = voltage leads current by 90 degrees. Think 'I'nductor = 'V'oltage 'L'eads. In an inductor, voltage leads current by 90°. Not current leading, not 180°, not in phase - just voltage leads by 90°.
Memory Aid
"Inductor AC relationship = voltage leads current by 90 degrees. Think 'I'nductor = 'V'oltage 'L'eads. In an inductor, voltage leads current by 90°. Important for circuit theory."
Real-World Application
AC current through an inductor and voltage across an inductor: The voltage leads the current by 90 degrees. This is because the inductor opposes current changes, so voltage appears before current builds up. This is the relationship - voltage leads current by 90°.
Key Concepts
Why Other Options Are Wrong
Option B: Incorrect. Current leads voltage by 90 degrees isn't correct - in an inductor, voltage leads current by 90°. Current leading is wrong.
Option C: Incorrect. Voltage and current are 180 degrees out of phase isn't correct - in an inductor, voltage leads current by 90°. 180° is wrong.
Option D: Incorrect. Voltage and current are in phase isn't correct - in an inductor, voltage leads current by 90°. In phase is wrong.
题目解析
The correct answer is A: Voltage leads current by 90 degrees. What is the relationship between the AC current through an inductor and the voltage across an inductor is that voltage leads current by 90 degrees. In an inductor, voltage leads current by 90°. For amateur radio operators, this is important for circuit theory. Understanding this helps when working with inductors.
考试技巧
Inductor AC relationship = voltage leads current by 90 degrees. Think 'I'nductor = 'V'oltage 'L'eads. In an inductor, voltage leads current by 90°. Not current leading, not 180°, not in phase - just voltage leads by 90°.
记忆口诀
Inductor AC relationship = voltage leads current by 90 degrees. Think 'I'nductor = 'V'oltage 'L'eads. In an inductor, voltage leads current by 90°. Important for circuit theory.
实际应用示例
AC current through an inductor and voltage across an inductor: The voltage leads the current by 90 degrees. This is because the inductor opposes current changes, so voltage appears before current builds up. This is the relationship - voltage leads current by 90°.
错误选项分析
Option B: Incorrect. Current leads voltage by 90 degrees isn't correct - in an inductor, voltage leads current by 90°. Current leading is wrong. Option C: Incorrect. Voltage and current are 180 degrees out of phase isn't correct - in an inductor, voltage leads current by 90°. 180° is wrong. Option D: Incorrect. Voltage and current are in phase isn't correct - in an inductor, voltage leads current by 90°. In phase is wrong.
知识点
AC current through inductor, Voltage across inductor, Voltage leads current, 90 degrees
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.