LENZ's LAW and FARADAY's LAW:
Lenz's law: the law of electromagnetic-mechanical opposition.
Lenz's law is basically a law of opposition to motion (change in position) and electromagnetic change. For motion, Lenz's law states that if a loop of wire moves while inside a magnetic field (from another source) then a current is produced in the moving wire that will produce its own magnetic field. This new magnetic field will react with the surrounding magnetic field in such a way that will try to oppose this motion (change in position). A similar thing occurs if you change the strength of the DC you are using in your loop of wire. Here, your changed DC generates its own magnetic field in such a way, that decreasing your DC has the same electromagnetic effect as moving your wire loop away from the surrounding magnetic field of the other source. In other words, due to changes in position (motion) and/or current, another current is created (INDUCED) with its OWN separate magnetic field.This is "action-at-a-distance, part 2"
Faraday's law: induced electrical current = (change in magnetic flux) / (change in time) / (total electrical resistance)
This is similar to, but NOT the same as Lenz's law: this law deals with specific quantities. It is also the OPPOSITE of theLorentz Deflection law mentioned earlier. Here, Faraday's law says that, not only do changes in position and current INDUCE other currents and magnetic field, but also their strengths depend also on the speed this was done. The idea here is that, if you CUT as much of the magnetic field as possible in as little time as possible, a current of specific strength is INDUCED. This often depends on the force you do use to accomplish this. In other words, the NEW current you create comes from the opposition (Lenz's law) to the force you supply as quickly as you can (Faraday's law = Lorentz law in reverse). This uses the same "right-hand-finger" convention mentioned earlier for the Lorentz Deflection, only here, you are "solving" for the INDUCED current instead of the deflection force. However, remember that even here, the RIGHT INDEX finger still points the direction of the induced current, and the RIGHT THUMB still points in the direction of the supplied force.
Below: the slip-ring apparatus is a good example of Lenz's and Faraday's laws at work. The ring that you see is forced down by its own gravitational force. The AC used to power this apparatus sets up a continuously changing magnetic field, which induces a current in the ring and produces a repelling force against the ring, which holds the ring up at a constant height. Thus, for this ring, its gravitation is electromagnetically "neutralized": gravitation still acts here, but there is enough EM repulsion created to counter act any acceleration due to gravitation, and the ring remains at a relatively stable height above this EM device.This is "action-at-a-distance, part 3".
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