What unit is used to measure reactance?
The correct answer is B: Ohm. The unit used to measure reactance is the ohm. Reactance, like resistance, is measured in ohms (Ω). For amateur radio operators, this is a fundamental unit. Understanding this helps when working with reactance values.
Exam Tip
Reactance unit = ohm. Think 'R'eactance = 'R'esistance-like, so 'O'hm. Reactance, like resistance, is measured in ohms (Ω). Not farad (capacitance), not ampere (current), not siemens (admittance) - just ohm.
Memory Aid
"Reactance unit = ohm. Think 'R'eactance = 'R'esistance-like, so 'O'hm. Reactance, like resistance, is measured in ohms (Ω). Standard unit for reactance measurement."
Real-World Application
An inductor has 100 ohms of inductive reactance at a certain frequency. A capacitor has 50 ohms of capacitive reactance. Reactance is measured in ohms, just like resistance. The ohm is the unit for both resistance and reactance.
Key Concepts
Why Other Options Are Wrong
Option A (Farad): Incorrect. Farad is the unit for capacitance, not reactance. Capacitance is measured in farads, reactance in ohms.
Option C (Ampere): Incorrect. Ampere is the unit for current, not reactance. Current is measured in amperes, reactance in ohms.
Option D (Siemens): Incorrect. Siemens is the unit for conductance/admittance, not reactance. Admittance is measured in siemens, reactance in ohms.
题目解析
The correct answer is B: Ohm. The unit used to measure reactance is the ohm. Reactance, like resistance, is measured in ohms (Ω). For amateur radio operators, this is a fundamental unit. Understanding this helps when working with reactance values.
考试技巧
Reactance unit = ohm. Think 'R'eactance = 'R'esistance-like, so 'O'hm. Reactance, like resistance, is measured in ohms (Ω). Not farad (capacitance), not ampere (current), not siemens (admittance) - just ohm.
记忆口诀
Reactance unit = ohm. Think 'R'eactance = 'R'esistance-like, so 'O'hm. Reactance, like resistance, is measured in ohms (Ω). Standard unit for reactance measurement.
实际应用示例
An inductor has 100 ohms of inductive reactance at a certain frequency. A capacitor has 50 ohms of capacitive reactance. Reactance is measured in ohms, just like resistance. The ohm is the unit for both resistance and reactance.
错误选项分析
Option A (Farad): Incorrect. Farad is the unit for capacitance, not reactance. Capacitance is measured in farads, reactance in ohms. Option C (Ampere): Incorrect. Ampere is the unit for current, not reactance. Current is measured in amperes, reactance in ohms. Option D (Siemens): Incorrect. Siemens is the unit for conductance/admittance, not reactance. Admittance is measured in siemens, reactance in ohms.
知识点
Reactance, Ohm, Unit of measurement, Electrical units
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.