Magnetism is a class of physical phenomena that are mediated by magnetic fields. Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. Every material is influenced to some extent by a magnetic field. Aristotle attributed the first of what could be called a scientific discussion on magnetism to Thales of Miletus, who lived from about 625 BC to about 545 BC. Around the same time, in ancient India, the Indian surgeon, Sushruta, was the first to make use of the magnet for surgical purposes
Electromagnetic induction is the production of an electromotive force across a conductor when it is exposed to a time varying magnetic field. It is described mathematically by Faraday’s law of induction, named after Michael Faraday, who is generally credited with the discovery of induction in 1831.
The law of physics describing the process of electromagnetic induction is known as Faraday’s law of induction and the most widespread version of this law states that the induced electromotive force in any closed circuit is equal to the rate of change of the magnetic flux enclosed by the circuit.
|Topical Notes, Problems, Presentation, Quiz, Test, AP Questions and Video lessons|
|Magnetic Force on a charged Particle|
|Magnetic Force on a current-carrying conductor|
|Electromagnetic induction: Faraday’s Laws|
|Test your Understanding: Chapter 3 MCQ Quiz 1 Here Take Chapter 3 ReQuiz MCQ Quiz 2 Here|
The magnetic state (or magnetic phase) of a material depends on temperature and other variables such as pressure and the applied magnetic field. A material may exhibit more than one form of magnetism as these variables change.