What is the unit of capacitance?
The correct answer is A: The farad. The unit of capacitance is the farad (abbreviated as 'F'), named after Michael Faraday. One farad is a very large unit - most capacitors are measured in microfarads (μF), nanofarads (nF), or picofarads (pF).
Capacitance measures how much charge a capacitor can store per volt. One farad means the capacitor can store one coulomb of charge when one volt is applied. In practice, you'll rarely see capacitors rated in farads - they're typically in microfarads (millionths of a farad), nanofarads (billionths), or picofarads (trillionths). Understanding the farad as the base unit helps with unit conversions.
Exam Tip
Capacitance unit = Farad. Remember: The unit of capacitance is the farad (F). Most capacitors are measured in microfarads (μF), nanofarads (nF), or picofarads (pF).
Memory Aid
"**C**apacitance = **F**arad (think 'C = F' = Capacitance = Farad)"
Real-World Application
A capacitor in your RF circuit might be rated at 0.001 microfarads (1 nanofarad or 1000 picofarads). All of these are ways of expressing the same capacitance value, with the farad as the base unit. Understanding that the farad is the unit of capacitance helps you understand capacitor specifications.
FCC Part 97.3Key Concepts
Why Other Options Are Wrong
Option B: Incorrect. The ohm is the unit of resistance, not capacitance. Resistance and capacitance are different properties.
Option C: Incorrect. The volt is the unit of voltage, not capacitance. Voltage and capacitance are different quantities.
Option D: Incorrect. The henry is the unit of inductance, not capacitance. Inductance and capacitance are different properties.
题目解析
The correct answer is A: The farad. The unit of capacitance is the farad (abbreviated as 'F'), named after Michael Faraday. One farad is a very large unit - most capacitors are measured in microfarads (μF), nanofarads (nF), or picofarads (pF). Capacitance measures how much charge a capacitor can store per volt. One farad means the capacitor can store one coulomb of charge when one volt is applied. In practice, you'll rarely see capacitors rated in farads - they're typically in microfarads (millionths of a farad), nanofarads (billionths), or picofarads (trillionths). Understanding the farad as the base unit helps with unit conversions.
考试技巧
Capacitance unit = Farad. Remember: The unit of capacitance is the farad (F). Most capacitors are measured in microfarads (μF), nanofarads (nF), or picofarads (pF).
记忆口诀
**C**apacitance = **F**arad (think 'C = F' = Capacitance = Farad)
实际应用示例
A capacitor in your RF circuit might be rated at 0.001 microfarads (1 nanofarad or 1000 picofarads). All of these are ways of expressing the same capacitance value, with the farad as the base unit. Understanding that the farad is the unit of capacitance helps you understand capacitor specifications.
错误选项分析
Option B: Incorrect. The ohm is the unit of resistance, not capacitance. Resistance and capacitance are different properties. Option C: Incorrect. The volt is the unit of voltage, not capacitance. Voltage and capacitance are different quantities. Option D: Incorrect. The henry is the unit of inductance, not capacitance. Inductance and capacitance are different properties.
知识点
Capacitance, Farad, Electrical units, Capacitors
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.