PHYS 2CL Lecture Notes - Lecture 5: Dipole Magnet, Inductor, Inductance
Document Summary
Magnetic fields result from: moving charges. Magnetic field circuits around current: dipole magnets. Can also add a medium which propagates magnetic field better than vacuum. Flux represents the amount of magnetic field passing through a surface. When flux changes through a loop it induces a voltage around that loop. Changing magnetic field through knife induces little current circles. The induced voltage from faraday"s law drives current through the loop. Current flowing in a loops creates its own magnetic field. This induced magnetic field opposes the original charge in magnetic flux. Stack two solenoids on top of each other. Alternating current generates a (changing) magnetic field. That changing field induces voltage/current in the top solenoid. Circuit elements that store energy in magnetic field. Inductors limit how quickly current can change in circuits. Current through an inductor generates a a magnetic field. Inductance measures how hard it is to change current through an inductor.