PHY 2020 Lecture Notes - Lecture 38: Phasor, Alternating Current, Angular Velocity
Document Summary
To explore and calculate resistance in ac circuit (called reactance) To diagram and solve examples of the series r-l-c circuit. To calculate and root-mean-square power in alternating-current circuits. To study resonance of series r-l-c circuit. Direct current (dc) does not vary with time: for example, battery powered devices, such as portalle audio players, cell phones, calculators, ect. use dc. Alternating current (ac) and also its voltage vary sinusoidally with time: any appliance tha you plug into a wall outlet uses ac. For ac, transformers could be used to step voltage up and down with ac. A coil of wire rotating with constant angular velocity in a magnetic field develops sinusoidal oscillating potential and current. The potential and current will vary from a maximum v and maximum i at a frequency. The usual circuit-diagram symbol for an ac sourced. (a) graphs of sinusoidal current and voltage versus time.
