What electrical component stores energy in an electric field?
The correct answer is B: Capacitor. A capacitor is the electrical component that stores energy in an electric field. Capacitors consist of two conductive plates separated by an insulator (dielectric), and they store energy in the electric field between the plates.
Capacitors are fundamental components that store electrical energy. When voltage is applied, electric charge accumulates on the plates, creating an electric field in the dielectric. This stored energy can be released when needed. Capacitors are used for filtering, coupling, timing, power supply smoothing, and many other applications. They're essential in radio circuits for tuning, filtering, and blocking DC while passing AC signals.
Exam Tip
Capacitor = Stores energy in electric field. Remember: Capacitors store energy in an electric field between conductive plates separated by a dielectric.
Memory Aid
"**C**apacitor = **E**lectric **F**ield **E**nergy (think 'C = EFE')"
Real-World Application
You're building a power supply filter. You add a capacitor across the output. When the power supply voltage is high, the capacitor charges, storing energy in its electric field. When voltage drops, the capacitor releases this energy, smoothing the output voltage. This is how capacitors store and release energy.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Varistors are voltage-dependent resistors used for surge protection. They don't store energy in an electric field - they change resistance with voltage.
Option C: Incorrect. Inductors store energy in a magnetic field, not an electric field. They're coils of wire that create magnetic fields when current flows.
Option D: Incorrect. Diodes are semiconductor devices that allow current in one direction. They don't store energy in an electric field - they're used for rectification and switching.
题目解析
The correct answer is B: Capacitor. A capacitor is the electrical component that stores energy in an electric field. Capacitors consist of two conductive plates separated by an insulator (dielectric), and they store energy in the electric field between the plates. Capacitors are fundamental components that store electrical energy. When voltage is applied, electric charge accumulates on the plates, creating an electric field in the dielectric. This stored energy can be released when needed. Capacitors are used for filtering, coupling, timing, power supply smoothing, and many other applications. They're essential in radio circuits for tuning, filtering, and blocking DC while passing AC signals.
考试技巧
Capacitor = Stores energy in electric field. Remember: Capacitors store energy in an electric field between conductive plates separated by a dielectric.
记忆口诀
**C**apacitor = **E**lectric **F**ield **E**nergy (think 'C = EFE')
实际应用示例
You're building a power supply filter. You add a capacitor across the output. When the power supply voltage is high, the capacitor charges, storing energy in its electric field. When voltage drops, the capacitor releases this energy, smoothing the output voltage. This is how capacitors store and release energy.
错误选项分析
Option A: Incorrect. Varistors are voltage-dependent resistors used for surge protection. They don't store energy in an electric field - they change resistance with voltage. Option C: Incorrect. Inductors store energy in a magnetic field, not an electric field. They're coils of wire that create magnetic fields when current flows. Option D: Incorrect. Diodes are semiconductor devices that allow current in one direction. They don't store energy in an electric field - they're used for rectification and switching.
知识点
Capacitor, Energy storage, Electric field, Electronic components
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.