Search results
Results from the WOW.Com Content Network
Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other. Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, magnetism is one of two aspects of electromagnetism .
4 Electricity and magnetism. 5 Heat. 6 Waves. 7 Gravity. 8 See also. 9 References. 10 Further reading. Toggle the table of contents.
A permanent magnet in such a field rotates so as to maintain its alignment with the external field. Magnetic torque is used to drive electric motors. In one simple motor design, a magnet is fixed to a freely rotating shaft and subjected to a magnetic field from an array of electromagnets. By continuously switching the electric current through ...
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).
Ørsted investigated and found the physical law describing the magnetic field, now known as Ørsted's law. Ørsted's discovery was the first connection found between electricity and magnetism, and the first of two laws that link the two; the other is Faraday's law of induction.
In October 2009, the national unemployment rate reached 10%, according to the Bureau of Labor Statistics. Three years later, though, it was still at 7.8%. By contrast, ...
Magnetic field (green) induced by a current-carrying wire winding (red) in a magnetic circuit consisting of an iron core C forming a closed loop with two air gaps G in it. In an analogy to an electric circuit, the winding acts analogously to an electric battery, providing the magnetizing field , the core pieces act like wires, and the gaps G act like resistors.
Ammonium nitrate, a specific component of fine particle air pollution primarily produced by agricultural emissions, is associated with decreased learning and memory performance in children aged ...