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The electromagnetic force is one of the four fundamental forces of nature. It is the dominant force in the interactions of atoms and molecules . Electromagnetism can be thought of as a combination of electrostatics and magnetism , which are distinct but closely intertwined phenomena.
Electromagnets often use a wire curled up into solenoid around an iron core which strengthens the magnetic field produced because the iron core becomes magnetised. [ 15 ] [ 16 ] Maxwell's extension to the law states that a time-varying electric field can also generate a magnetic field. [ 12 ]
A portative electromagnet is one designed to just hold material in place; an example is a lifting magnet. A tractive electromagnet applies a force and moves something. [8] Electromagnets are very widely used in electric and electromechanical devices, including: Motors and generators; Transformers; Relays; Electric bells and buzzers ...
Mechanical work is necessary to drive this current. When the generated current flows through the conducting rim, a magnetic field is generated by this current through Ampère's circuital law (labelled "induced B" in the figure). The rim thus becomes an electromagnet that resists rotation of the disc (an example of Lenz's law). On the far side ...
Electromagnetic propulsion (EMP) is the principle of accelerating an object by the utilization of a flowing electrical current and magnetic fields.The electrical current is used to either create an opposing magnetic field, or to charge a field, which can then be repelled.
The Maxwell–Faraday equation (listed as one of Maxwell's equations) describes the fact that a spatially varying (and also possibly time-varying, depending on how a magnetic field varies in time) electric field always accompanies a time-varying magnetic field, while Faraday's law states that emf (electromagnetic work done on a unit charge when ...
A notable application of visible light is that this type of energy from the Sun powers all life on Earth that either makes or uses oxygen. A changing electromagnetic field which is physically close to currents and charges (see near and far field for a definition of "close") will have a dipole characteristic that is dominated by either a ...
Superconducting magnets have a number of advantages over resistive electromagnets. They can generate much stronger magnetic fields than ferromagnetic-core electromagnets, which are limited to fields of around 2 T. The field is generally more stable, resulting in less noisy measurements.