What is the unit of inductance?
The correct answer is C: The henry. The unit of inductance is the henry (abbreviated as 'H'), named after Joseph Henry. One henry is a relatively large unit - most inductors are measured in millihenries (mH) or microhenries (μH).
Inductance measures how much magnetic flux is created per ampere of current. One henry means the inductor creates one weber of magnetic flux when one ampere flows through it. In practice, you'll commonly see inductors rated in millihenries (thousandths of a henry) or microhenries (millionths of a henry). Understanding the henry as the base unit helps with unit conversions and circuit calculations.
Exam Tip
Inductance unit = Henry. Remember: The unit of inductance is the henry (H). Most inductors are measured in millihenries (mH) or microhenries (μH).
Memory Aid
"**I**nductance = **H**enry (think 'I = H' = Inductance = Henry)"
Real-World Application
An inductor in your RF circuit might be rated at 10 microhenries (0.00001 henries). This is a common inductance value for RF inductors. Understanding that the henry is the unit of inductance helps you understand inductor specifications and perform circuit calculations.
FCC Part 97.3Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. The coulomb is the unit of electric charge, not inductance. Charge and inductance are different quantities.
Option B: Incorrect. The farad is the unit of capacitance, not inductance. Capacitance and inductance are different properties.
Option D: Incorrect. The ohm is the unit of resistance, not inductance. Resistance and inductance are different properties.
题目解析
The correct answer is C: The henry. The unit of inductance is the henry (abbreviated as 'H'), named after Joseph Henry. One henry is a relatively large unit - most inductors are measured in millihenries (mH) or microhenries (μH). Inductance measures how much magnetic flux is created per ampere of current. One henry means the inductor creates one weber of magnetic flux when one ampere flows through it. In practice, you'll commonly see inductors rated in millihenries (thousandths of a henry) or microhenries (millionths of a henry). Understanding the henry as the base unit helps with unit conversions and circuit calculations.
考试技巧
Inductance unit = Henry. Remember: The unit of inductance is the henry (H). Most inductors are measured in millihenries (mH) or microhenries (μH).
记忆口诀
**I**nductance = **H**enry (think 'I = H' = Inductance = Henry)
实际应用示例
An inductor in your RF circuit might be rated at 10 microhenries (0.00001 henries). This is a common inductance value for RF inductors. Understanding that the henry is the unit of inductance helps you understand inductor specifications and perform circuit calculations.
错误选项分析
Option A: Incorrect. The coulomb is the unit of electric charge, not inductance. Charge and inductance are different quantities. Option B: Incorrect. The farad is the unit of capacitance, not inductance. Capacitance and inductance are different properties. Option D: Incorrect. The ohm is the unit of resistance, not inductance. Resistance and inductance are different properties.
知识点
Inductance, Henry, Electrical units, Inductors
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.