General
Physics
Faraday’s Law of Induction
Faraday's law of induction is a fundamental principle in the field of electricity that explains the relationship between a changing magnetic field and the induced electric current in a conductor. This law was discovered by British scientist Michael Faraday in the early 19th century and is considered one of the most important laws in the field of electromagnetism.
The law states that the induced electric current in a conductor is directly proportional to the rate of change of the magnetic flux through the conductor. Magnetic flux refers to the number of magnetic field lines passing through a given area and is measured in units of Weber (Wb). The rate of change of the magnetic flux is also known as the "time-derivative" of the flux, and it is measured in units of Tesla per second (T/s).
To better understand the relationship between the magnetic flux and the induced current, imagine a simple circuit with a coil of wire. When a magnet is moved towards or away from the coil, the number of magnetic field lines passing through the coil changes, causing a change in the magnetic flux. As a result of this change, an electric current is induced in the coil. The stronger the change in the magnetic flux, the greater the induced current will be.

This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
Faraday's law of induction can be mathematically represented by the following equation:
EMF = -N * (dΦ/dt)
Where EMF represents the induced electric potential (or "electromotive force" in volts), N is the number of turns in the coil and dΦ/dt is the rate of change of the magnetic flux. This equation tells us that the induced electric potential is directly proportional to the rate of change of the magnetic flux and the number of turns in the coil.
Faraday's law of induction has many practical applications, including in the generation of electricity in power plants, in electric motors and in the operation of transformers. Additionally, Faraday's law is the basis for many electrical devices, such as generators, alternators, and electric motors.
Continue the lesson
This section is available to learners with course access. Continue learning with Knowness to unlock the full explanation, examples, revision tools, and progress tracking.
The remaining lesson content includes further guided explanation, important learning points, and supporting interactive material designed to help you understand and revise this topic.
Unlock this topic to view the full activity, worked examples, common mistakes, and additional revision support.
More content available
Knowness lessons are structured to build understanding step by step. Create an account or upgrade your access to continue from this point.
This preview does not include the hidden lesson text, answers, explanations, or embedded interactions.
Continue learning with Knowness
Sign up to access the full lesson, predicted grades, revision tools, progress tracking, and more.
Create a free account