>>16238263Magnetic fields are caused by moving charge (either in the form of charge*velocity (ex. electron) or current (by definition, charge/time).
Your book (if you don't have one, download it online; pirate bay has most standard text books) should have the equations for B, the magnetic field, of a point charge, wire, and loop.
Ampere's law is used to figure out what B is when given current, and the length of the line where you're measuring B. If you can't bother reading anything, this is the equation you use to figure out B/I (current)/delta S (length) given the other two.
Similar to electric fields (F=qE), the force exerted by a magnetic field is F = q*vxB (cross product), or F=q*v*Bsin(theta).
For a wire, F = I*Length*B.
Faraday's Law tells us that changing B gives produces current, which (from V=IR) in any system with Resistance, gives us voltage.
Magnetic Flux, similar to electrical flux, is a concept that tells us how 'much' of a magnetic field passes through an area, given by Φ = A dot B = A*Bcos(theta), where A is the area (with randomly assigned direction as to be a vector).
Emf (read: Voltage) = |(change in Φ)/(change in time)|. Learn to use that equation, as it related voltage (and through V=IR, current and resistance) and flux (which is just magnetic field and area).
Inductors are set up, yes to resist current. Usually using AC as your V source, it creates an changing current. This changing current creates a new change in magnetic field (Faraday's Law). As you should know, a change in magnetic field produces current (F's Law again), a new one in response to the new deltaB. This current induced/created is such that it opposes change in flux, as shown by Lenz's Law (look it up and read it).
Honestly, physics isn't so bad as long as you understand the formulas and how to apply them. If you don't, use your book's chapter problems until you do; you can find teacher's solutions manual online for most textbooks if you really need help).
