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Michael Faraday developed the concept of lines of force to describe electric and magnetic phenomena. [14] In 1831, he writes [14] By magnetic curves, I mean the lines of magnetic forces, however modified by the juxtaposition of poles, which would be depicted by iron filings; or those to ·which a very small magnetic needle would form a tangent."
An electromagnet attracts paper clips when current is applied, creating a magnetic field. The electromagnet loses them when current and magnetic field are removed. An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. [17] The magnetic field disappears when the current is turned off.
Advanced Placement (AP) Physics C: Electricity and Magnetism (also known as AP Physics C: E&M or AP E&M) is an introductory physics course administered by the College Board as part of its Advanced Placement program. It is intended to serve as a proxy for a second-semester calculus-based university course in electricity and magnetism.
1864 – James Clerk Maxwell publishes his papers on a dynamical theory of the electromagnetic field; 1865 – James Clerk Maxwell publishes his landmark paper A Dynamical Theory of the Electromagnetic Field, in which Maxwell's equations demonstrated that electric and magnetic forces are two complementary aspects of electromagnetism.
Authors usually derive magnetism from electrostatics when special relativity and charge invariance are taken into account. The Feynman Lectures on Physics (vol. 2, ch. 13–6) uses this method to derive the magnetic force on charge in parallel motion next to a current-carrying wire.
Ancient people learned about magnetism from lodestones (or magnetite) which are naturally magnetized pieces of iron ore.The word magnet was adopted in Middle English from Latin magnetum "lodestone", ultimately from Greek μαγνῆτις [λίθος] (magnētis [lithos]) [1] meaning "[stone] from Magnesia", [2] a place in Anatolia where lodestones were found (today Manisa in modern-day Turkey).
Einstein's 1905 paper that introduced the world to relativity opens with a description of the magnet/conductor problem: [3]. It is known that Maxwell's electrodynamics – as usually understood at the present time – when applied to moving bodies, leads to asymmetries which do not appear to be inherent in the phenomena.
The definitions for monopoles are of theoretical interest, although real magnetic dipoles can be described using pole strengths. There are two possible units for monopole strength, Wb (Weber) and A m (Ampere metre). Dimensional analysis shows that magnetic charges relate by q m (Wb) = μ 0 q m (Am).