Inductor

Definition

An inductor is a passive electrical component that stores energy in a magnetic field when electric current flows through it. This energy storage capability allows inductors to oppose changes in current, making them crucial in various applications such as filters, oscillators, and energy storage systems. Their behavior is described by inductance, which is measured in henries (H) and reflects the inductor's ability to resist changes in current flow.

5 Must Know Facts For Your Next Test

1. Inductors are commonly found in power supplies and audio equipment, where they help smooth out current fluctuations.
2. The inductance of an inductor depends on its physical properties, including the number of coils, the core material, and the size of the coil.
3. When the current flowing through an inductor changes, it generates a back electromotive force (EMF) that opposes the change, described by Lenz's law.
4. Inductors can be either air-cored or core-coupled with materials like iron to enhance their magnetic properties and increase inductance.
5. In alternating current (AC) circuits, inductors create reactance that varies with frequency, which is vital for tuning circuits and filters.

Review Questions

• How does an inductor behave when there is a sudden change in current flow?
  • When there is a sudden change in current flow through an inductor, it generates a back electromotive force (EMF) that opposes the change. This means if the current tries to increase, the inductor resists this increase by generating a voltage in the opposite direction. Conversely, if the current decreases suddenly, the inductor tries to maintain the current by providing voltage. This property helps stabilize current flow and prevents abrupt changes.
• Discuss how inductors are utilized in filters within electrical circuits.
  • Inductors are essential components in filter circuits where they work alongside capacitors to control the frequency response of signals. In low-pass filters, inductors allow low-frequency signals to pass while attenuating higher frequencies due to their increasing reactance with frequency. In high-pass filters, they block low-frequency signals while allowing high frequencies to pass. By combining inductors and capacitors, engineers can design circuits that selectively filter out unwanted frequencies from electrical signals.
• Evaluate the impact of inductance on the design of an LC circuit and its resonance characteristics.
  • In an LC circuit, both inductance (L) and capacitance (C) play crucial roles in determining its resonance characteristics. The resonance frequency of an LC circuit is given by the formula $$f_0 = \frac{1}{2\pi\sqrt{LC}}$$. As inductance increases, the resonance frequency decreases, meaning lower frequencies are favored for oscillation. This relationship impacts how these circuits are designed for various applications like radio transmitters or oscillators. A well-designed LC circuit can achieve desired oscillation characteristics and stability by carefully selecting appropriate values for L and C.

Related terms

Capacitor:

A passive electrical component that stores energy in an electric field, often used in filtering and timing applications.

Resistor: An electrical component that opposes the flow of current, converting electrical energy into heat, and used for controlling voltage and current levels.

LC Circuit: An electric circuit that consists of an inductor (L) and a capacitor (C) connected together, which can oscillate at a particular frequency determined by the values of L and C.