ELEC1103 Lecture Notes - Lecture 12: Electric Field, Qi

• School: University of Sydney
• Department: Electrical Engineering
• Course: ELEC1103
• Professor: omid kavehei

Document Summary

Impedance is the ac analogue of dc resistance and is measured in ohms. Slightly more complicated because you have to consider the frequency of the current. Capacitors store electric charge in an electric field. Even when the capacitor is disconnected from a power source, it keeps its potential difference. They can block dc while allowing ac current to flow. They smooth the output of power supplies. They can be used to tune radios. When connected to positive and negative terminals, electrons are dragged away from one end of the capacitor and deposited in the other end. For there is an exactly equal and opposite amount of charge in either end of a capacitor. Even if the anode and cathode are different sizes, shapes, and materials. The accumulated charge occurs when the attraction between the positive terminal of the battery and the now positively charged capacitor plate are equal, resulting in no movement of electrons in the circuit.