Faraday Discovers Electromagnetic Induction
A moving magnet makes an electric current, and the dynamo and the electric age follow from it
Quick facts
- Discovery
- Electromagnetic induction, 1831
- Institution
- Royal Institution, London
- Key device
- First dynamo (electricity from mechanical motion)
- Conceptual legacy
- Lines of force, ancestor of the field concept
What happened
Michael Faraday, working at the Royal Institution in London, found in 1831 that a changing magnetic field could induce an electric current in a nearby wire, a phenomenon now called electromagnetic induction. MacTutor's account of Faraday's career notes that his experiments showed a magnet could induce an electrical current in a wire, letting him convert mechanical energy into electrical energy and build what is recognized as the first dynamo, since his apparatus recorded the first conversion of electrical into mechanical energy as well. Faraday, who lacked advanced mathematical training, explained his results using a physical picture rather than equations: he described lines of force filling the space around magnets and charges, a concept MacTutor identifies as central to his thinking throughout his career and the ancestor of the modern idea of a field.
Why it matters
Faraday's induction is the physical principle behind every electric generator and transformer built since, making it one of the most economically consequential discoveries in the history of physics. His qualitative concept of lines of force, developed without the calculus that trained physicists of his era used, gave James Clerk Maxwell the physical picture he would later translate into exact mathematical field equations.
How we know
Faraday recorded his induction experiments in detail in his own diaries and read his results to the Royal Society in November 1831; MacTutor's biography draws directly on this documented experimental record and on Faraday's published papers.
Sources
- MacTutor History of Mathematics, University of St Andrews. Michael Faraday (1791 - 1867) · Primary source (author-declared)mathshistory.st-andrews.ac.uk · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- PMC, National Library of Medicine. The birth of the electric machines: a commentary on Faraday (1832) 'Experimental researches in electricity' · Peer-reviewedpmc.ncbi.nlm.nih.gov · The domain "pmc.ncbi.nlm.nih.gov" is on our Peer-reviewed registry. · Link is live and its text matches the event's key terms (Jul 2026)
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