What describes the ability to store energy in a magnetic field?
The correct answer is D: Inductance. Inductance describes the ability to store energy in a magnetic field. An inductor (coil) stores electrical energy by creating a magnetic field when current flows through it.
When current flows through an inductor (a coil of wire), it creates a magnetic field around the coil. Energy is stored in this magnetic field. The amount of energy stored depends on the inductance value (measured in henries) and the current flowing. When the current changes, the magnetic field changes, and the stored energy can be released back into the circuit. Inductors are essential components in radio circuits for filtering, tuning, and impedance matching.
Exam Tip
Store energy in magnetic field = Inductance. Remember: Inductance is the ability to store energy in a magnetic field. Inductors (coils) do this.
Memory Aid
"**I**nductance = **I**nductor **M**agnetic **F**ield (think 'I = IMF' = Inductor Magnetic Field)"
Real-World Application
An inductor (coil) in your RF circuit stores energy in its magnetic field. When current flows through the coil, it creates a magnetic field that stores energy. This stored energy can help filter signals or tune circuits. The inductor's inductance value (in henries) determines how much energy it can store.
FCC Part 97.3Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Admittance is the inverse of impedance (how easily current flows), not the ability to store energy in a magnetic field.
Option B: Incorrect. Capacitance is the ability to store energy in an electric field, not a magnetic field. Capacitors store energy in electric fields.
Option C: Incorrect. Resistance opposes current flow and dissipates energy as heat. It doesn't store energy in a magnetic field.
题目解析
The correct answer is D: Inductance. Inductance describes the ability to store energy in a magnetic field. An inductor (coil) stores electrical energy by creating a magnetic field when current flows through it. When current flows through an inductor (a coil of wire), it creates a magnetic field around the coil. Energy is stored in this magnetic field. The amount of energy stored depends on the inductance value (measured in henries) and the current flowing. When the current changes, the magnetic field changes, and the stored energy can be released back into the circuit. Inductors are essential components in radio circuits for filtering, tuning, and impedance matching.
考试技巧
Store energy in magnetic field = Inductance. Remember: Inductance is the ability to store energy in a magnetic field. Inductors (coils) do this.
记忆口诀
**I**nductance = **I**nductor **M**agnetic **F**ield (think 'I = IMF' = Inductor Magnetic Field)
实际应用示例
An inductor (coil) in your RF circuit stores energy in its magnetic field. When current flows through the coil, it creates a magnetic field that stores energy. This stored energy can help filter signals or tune circuits. The inductor's inductance value (in henries) determines how much energy it can store.
错误选项分析
Option A: Incorrect. Admittance is the inverse of impedance (how easily current flows), not the ability to store energy in a magnetic field. Option B: Incorrect. Capacitance is the ability to store energy in an electric field, not a magnetic field. Capacitors store energy in electric fields. Option C: Incorrect. Resistance opposes current flow and dissipates energy as heat. It doesn't store energy in a magnetic field.
知识点
Inductance, Energy storage, Magnetic field, Inductors
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.