What describes the ability to store energy in an electric field?
The correct answer is D: Capacitance. Capacitance describes the ability to store energy in an electric field. A capacitor stores electrical energy by accumulating charge on its plates, creating an electric field between them.
When voltage is applied to a capacitor, electrons accumulate on one plate (making it negative) and are removed from the other plate (making it positive). This creates an electric field between the plates, and energy is stored in this field. The amount of energy a capacitor can store depends on its capacitance value (measured in farads) and the voltage applied. Capacitors are essential components in radio circuits for filtering, coupling, and tuning.
Exam Tip
Store energy in electric field = Capacitance. Remember: Capacitance is the ability to store energy in an electric field. Capacitors do this.
Memory Aid
"**C**apacitance = **C**harge **E**lectric **F**ield (think 'C = CEF' = Charge Electric Field)"
Real-World Application
A capacitor in your power supply stores energy in its electric field. When voltage is applied, charge accumulates on the capacitor plates, creating an electric field that stores energy. This stored energy can help smooth out voltage variations. The capacitor's capacitance value (in farads) determines how much energy it can store.
FCC Part 97.3Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Inductance is the ability to store energy in a magnetic field, not an electric field. Inductors store energy in magnetic fields.
Option B: Incorrect. Resistance opposes current flow and dissipates energy as heat. It doesn't store energy in an electric field.
Option C: Incorrect. Tolerance is a specification for component value accuracy, not an energy storage property.
题目解析
The correct answer is D: Capacitance. Capacitance describes the ability to store energy in an electric field. A capacitor stores electrical energy by accumulating charge on its plates, creating an electric field between them. When voltage is applied to a capacitor, electrons accumulate on one plate (making it negative) and are removed from the other plate (making it positive). This creates an electric field between the plates, and energy is stored in this field. The amount of energy a capacitor can store depends on its capacitance value (measured in farads) and the voltage applied. Capacitors are essential components in radio circuits for filtering, coupling, and tuning.
考试技巧
Store energy in electric field = Capacitance. Remember: Capacitance is the ability to store energy in an electric field. Capacitors do this.
记忆口诀
**C**apacitance = **C**harge **E**lectric **F**ield (think 'C = CEF' = Charge Electric Field)
实际应用示例
A capacitor in your power supply stores energy in its electric field. When voltage is applied, charge accumulates on the capacitor plates, creating an electric field that stores energy. This stored energy can help smooth out voltage variations. The capacitor's capacitance value (in farads) determines how much energy it can store.
错误选项分析
Option A: Incorrect. Inductance is the ability to store energy in a magnetic field, not an electric field. Inductors store energy in magnetic fields. Option B: Incorrect. Resistance opposes current flow and dissipates energy as heat. It doesn't store energy in an electric field. Option C: Incorrect. Tolerance is a specification for component value accuracy, not an energy storage property.
知识点
Capacitance, Energy storage, Electric field, Capacitors
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.