How does electromagnetic induction work in transformers?

Transformers transfer electrical energy between circuits through electromagnetic induction without any metallic connection between them. A varying current in one coil creates a changing magnetic flux in the core, which induces an electromotive force in other coils wound around the same core. This process relies on Faraday's law of induction, where a time-varying magnetic field produces a circulating electric field.

What we know

• A varying current in any coil of a transformer produces a varying magnetic flux in its core. [4]
• The changing magnetic flux in the core induces a varying electromotive force across any other coils wound around the same core. [4]
• Electrical energy is transferred between separate coils without a metallic or conductive connection between the circuits. [4]
• In transformer emf, a time-varying magnetic field induces an electric field that drives a current around a conducting loop. [3]

Where to go next

• whoWho discovered electromagnetic induction?
• how it workedHow does the Maxwell-Faraday equation describe induction?
• a case in pointWhat are step-up and step-down transformers?
• compared withWhat is motional emf?
• the bigger pictureWhat are the broader applications of electromagnetic induction?
• an unexpected connectionHow did an induction coil power early medical devices?An early type of transformer known as the induction coil was surprisingly used in quack medical electrotherapy devices from the 1880s to the 1920s.

Sources

• [1]Electromagnetic induction (Wikidata Q988780) · CC0 1.0
• [2]Electromagnetic induction · CC BY-SA 4.0
• [3]Faraday's law of induction · CC BY-SA 4.0
• [4]Transformer · CC BY-SA 4.0
• [5]Induction coil · CC BY-SA 4.0