Lecture : PHYS272 Module 2 CIRCUITS Revision Spring 2023
Document Summary
Kirchhoff"s rules: voltage loop rule and current node rule emf = energy input per unit charge. A battery is in the circuit to provide a potential difference / charge separation. Just after a circuit is connected (transition from equilibrium to steady state) This is a very big difference! drift speed = It takes very long (days) for electrons to actually travel in circuits. The change in the electric field (the propagation) is almost instant. Theory (how quickly does a circuit actually light up ?) from out perspective, the electrons are slow but from the electrons perspective, they are very fast. Surface charges, potential differences and states of circuits u = electron mobility (varies for dif. materials) Energy supplied by battery some electrons collide with the lattice. In a connected circuit, the surface charges align automatically to maintain constant. Equilibrium means when the constant current is equal to zero (no flow of charge) steady state means constant current and constant field.
