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Unformatted text preview: Inductors Not only can a current be induced in a coil by an external magnetic flux changing with time ( V=-N ∆ Φ / ∆ t ), but a coil can induce a current in itself using the magnetic field it generates when a current is passing through it. This is by no mean perpetual motion, but it makes a coil resistant to changes in the current flowing through it in a manner very similar to how mass resists changes in speed by way of its momentum. A third basic passive element in circuits is the inductor . Basically, it is a small coil, and like resistors and capacitors, there are a few simple equations that describe its behavior. The proper measure of an inductor is the inductance , which is given the symbol L and is quantified using a unit called a henry ( H ). When the only magnetic field influencing an inductor is its own, L = N Φ /I . Since inductors are usually solenoids, and since the solenoid’s coils are perpendicular to their own interior magnetic field, Φ = AB = A µ ₀ NI/ l , so...
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This note was uploaded on 04/05/2012 for the course PHYS 131 taught by Professor Tibbets during the Spring '11 term at Cuyamaca College.
- Spring '11