Inductors

Definition

Inductors are passive electronic components that store energy in the form of a magnetic field when an electric current passes through them. They are fundamental elements in electrical circuits and play a crucial role in various applications, including power supplies, filters, and timing circuits.

5 Must Know Facts For Your Next Test

1. Inductors are made by winding a conductive wire, typically copper, around a core material, which can be air, ferromagnetic, or ferrimagnetic.
2. The amount of inductance, measured in henries (H), depends on the number of turns in the coil, the cross-sectional area of the coil, and the permeability of the core material.
3. Inductors oppose changes in current, which is known as the property of self-inductance, and this property is used in various electronic circuits to filter, store energy, and control current.
4. Mutual inductance is the phenomenon where a changing current in one inductor can induce a voltage in another nearby inductor, and this is the basis for transformers and other inductive coupling devices.
5. Inductors are essential components in the Biot-Savart law, which describes the magnetic field generated by a current-carrying wire, and in the concept of mutual inductance, which is important for understanding transformer operation.

Review Questions

• Explain how the property of self-inductance in an inductor can be used to filter or control current in an electronic circuit.
  • The self-inductance of an inductor causes it to oppose changes in the current flowing through it. This property can be used to filter out unwanted high-frequency signals or to control the rate of current change in a circuit. For example, in a power supply, an inductor can be used to smooth out the ripple in the output voltage by opposing rapid changes in current. Additionally, inductors can be used in timing circuits to control the rate of current change, which is important for applications like oscillators and switching regulators.
• Describe how the concept of mutual inductance between two inductors is used in the operation of transformers.
  • Mutual inductance is the phenomenon where a changing current in one inductor can induce a voltage in another nearby inductor. This principle is the basis for the operation of transformers, which are devices that use two or more coupled inductors to transfer electrical energy between circuits. When an alternating current flows through the primary winding of a transformer, it creates a changing magnetic field that induces a voltage in the secondary winding. The ratio of the number of turns in the primary and secondary windings determines the transformation ratio, allowing transformers to be used for tasks such as stepping up or down voltage levels in power distribution systems.
• Analyze how the Biot-Savart law, which describes the magnetic field generated by a current-carrying wire, is related to the behavior of inductors.
  • The Biot-Savart law states that the magnetic field generated by a current-carrying wire is proportional to the current and inversely proportional to the distance from the wire. This relationship is fundamental to the operation of inductors, as the magnetic field generated by the current flowing through the inductor's coil is what allows the inductor to store energy and exhibit the property of self-inductance. The Biot-Savart law can be used to calculate the magnetic field within an inductor, which is then used to determine the inductor's inductance and its behavior in electrical circuits. Understanding the Biot-Savart law is crucial for analyzing the performance and design of inductors in various applications.

Related terms

Magnetic Flux: The measure of the total magnetic field passing through a given surface, often used to describe the magnetic field generated by an inductor.

Self-Inductance: The property of an inductor that describes the amount of voltage induced in the inductor due to a change in the current flowing through it.

Faraday's Law of Electromagnetic Induction: The law that states that a changing magnetic field will induce an electromotive force (EMF) in a conductor, which is the fundamental principle behind the operation of inductors.