General Physics 2 - Capacitors PDF
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This document details the properties of capacitors, including capacitance, parallel and series combinations. It provides explanations along with worked examples. Key concepts like capacitance are examined in detail, offering several sample problems including parallel and series circuits.
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# General Physics 2 ## Capacitors - An element that stores charge when voltage is applied. - A capacitor consists of two conductors called plates. - When the conductor is charged, the plates carry charges of equal magnitude and opposite directions. ## Factors Affecting Capacitance - The area of...
# General Physics 2 ## Capacitors - An element that stores charge when voltage is applied. - A capacitor consists of two conductors called plates. - When the conductor is charged, the plates carry charges of equal magnitude and opposite directions. ## Factors Affecting Capacitance - The area of the plates. - The distance between the plates. - The ability of the dielectric to support the electrostatic forces. ## Capacitance - The capacitance (C) of a capacitor is defined as the ratio of the magnitude of the charge on either conductor to the potential difference between the conductors. - C = Q / V - The SI unit of capacitance is farad (F). - The farad is a large unit; microfarads (uF) and picofarads (pF) are more common units of capacitance. ## Capacitance in Parallel - When capacitors are first connected in the circuit, electrons are transferred from the left plates through the battery to the right plate. - The potential difference across the capacitors is the same and each is equal to the voltage of the battery. - V<sub>total</sub> = V<sub>1</sub> = V<sub>2</sub> = V<sub>3</sub> - The total charge is equal to the sum of the charges on the capacitors. - Q<sub>total</sub> = Q<sub>1</sub> + Q<sub>2</sub> + Q<sub>3</sub> - The capacitors can be replaced with one capacitor with a capacitance of C<sub>eq</sub>. - C<sub>eq</sub> = C<sub>1</sub> + C<sub>2</sub> - The equivalent capacitance of a parallel combination of capacitors is greater than any of the individual capacitors. ## Capacitance in Series - All the right plates gain charges of -Q and all the left plates have charges of +Q. - The charges are all the same. - Q<sub>total</sub> = Q<sub>1</sub> = Q<sub>2</sub> - The voltage add up to the battery voltage. - V<sub>total</sub> = V<sub>1</sub> + V<sub>2</sub> + ... - The equivalent capacitance is: - 1/C<sub>eq</sub> = 1/C<sub>1</sub> + 1/C<sub>2</sub> + 1/C<sub>3</sub> + .... - The equivalent capacitance of a series combination is always less than any individual capacitor in the combination. ## Capacitors in Circuits A diagram of several capacitors is shown. The values of the different capacitors are labelled, and then additional information is provided about the circuit. This document presents a series of images and explanations. Several sample problems are provided to illustrate parallel and series capacitance, and show how to calculate the total capacitance of the entire circuit.
