What type of electrical component stores energy in a magnetic field?
The correct answer is C: Inductor. An inductor is the type of electrical component that stores energy in a magnetic field. Inductors are coils of wire that create magnetic fields when current flows, storing energy in that magnetic field.
Inductors are coils of wire (often wound around a core) that store energy in a magnetic field. When current flows through the coil, it creates a magnetic field around it. This magnetic field stores energy. When the current changes, the magnetic field changes, inducing voltage (inductance). Inductors are used for filtering, tuning, impedance matching, and many RF applications. They're essential in radio circuits for resonant circuits, filters, and impedance transformation.
Exam Tip
Inductor = Stores energy in magnetic field. Remember: Inductors are coils of wire that store energy in a magnetic field created when current flows through them.
Memory Aid
"**I**nductor = **M**agnetic **F**ield **E**nergy (think 'I = MFE')"
Real-World Application
You're building an RF filter. You wind a coil of wire to make an inductor. When current flows through the coil, it creates a magnetic field around it, storing energy. When the current changes, the magnetic field changes, affecting the circuit's behavior. This is how inductors store energy in a magnetic field.
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 a magnetic field - they change resistance with voltage.
Option B: Incorrect. Capacitors store energy in an electric field, not a magnetic field. They use conductive plates separated by a dielectric.
Option D: Incorrect. Diodes are semiconductor devices that allow current in one direction. They don't store energy in a magnetic field - they're used for rectification and switching.
题目解析
The correct answer is C: Inductor. An inductor is the type of electrical component that stores energy in a magnetic field. Inductors are coils of wire that create magnetic fields when current flows, storing energy in that magnetic field. Inductors are coils of wire (often wound around a core) that store energy in a magnetic field. When current flows through the coil, it creates a magnetic field around it. This magnetic field stores energy. When the current changes, the magnetic field changes, inducing voltage (inductance). Inductors are used for filtering, tuning, impedance matching, and many RF applications. They're essential in radio circuits for resonant circuits, filters, and impedance transformation.
考试技巧
Inductor = Stores energy in magnetic field. Remember: Inductors are coils of wire that store energy in a magnetic field created when current flows through them.
记忆口诀
**I**nductor = **M**agnetic **F**ield **E**nergy (think 'I = MFE')
实际应用示例
You're building an RF filter. You wind a coil of wire to make an inductor. When current flows through the coil, it creates a magnetic field around it, storing energy. When the current changes, the magnetic field changes, affecting the circuit's behavior. This is how inductors store energy in a magnetic field.
错误选项分析
Option A: Incorrect. Varistors are voltage-dependent resistors used for surge protection. They don't store energy in a magnetic field - they change resistance with voltage. Option B: Incorrect. Capacitors store energy in an electric field, not a magnetic field. They use conductive plates separated by a dielectric. Option D: Incorrect. Diodes are semiconductor devices that allow current in one direction. They don't store energy in a magnetic field - they're used for rectification and switching.
知识点
Inductor, Energy storage, Magnetic field, Electronic components
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.