University:
Kentucky State University
Course:
PHY 212 | General Physics II
Academic year:

2024
Views:

346

Pages:

3
Author:

Athena Harrison

Capacitors: the basics What is a capacitor? It is a device for storing charge. A A capacitor is any configuration of two conductors that are close but not touching. The conductors carry charges of equal magnitude and opposite sign. Thus, a potential difference exists between the plates i.e. across the capacitor. Capacitors in circuits symbol for capacitor (think parallel plates) symbol for battery, or external potential battery voltage V is actually potential difference between the terminals Parallel Plate Capacitor + V Capacitor in a circuit Capacitor plates build up charges +Q and –Q. When battery is disconnected, charge remains on plates. Capacitance How much charge can a capacitor store? Experiment shows that when a capacitor is connected to a battery, the charge Q on its plates is proportional to the battery voltage V, with the proportionality constant equal to the Capacitance C. Capacitance: Q C V V is really |V|, the potential difference across the capacitor The SI unit of capacitance is the Farad (F) , 1 F = 1 C/V Capacitance: Is always a positive quantity. It is a device property. Is constant for a given capacitor, depends on geometry. Is a measure of the capacitor’s ability to store charge micro 10-6, nano 10-9, pico 10-12 (Know for exam!)