-Capacitor stores electric potential energy and electric charge-Insulating two conductors = a capacitor-To store energy, transfer charge from one conductor to the other so they both have the same charge, opposite sign-Work needed to move charges through the resulting potential difference, work is stored as electric potential energy24.1 Capacitors and Capacitance:-Capacitors = any two conductors separated by an insulator/vacuum-A capacitor w/ charge Q means the conductor @ higher potential has charge +Q and the conductor @ lower potential has charge -Q-Capacitance:C = Q/V_ab-Charge the conductors to charge +Q and -Q, disconnect the battery = FIXED POTENTIAL DIFFERENCE V_ab between the conductors = to voltage of the battery-1 Farad = 1 F = 1 C/V-Capacitance = measure of ability of capacitor to store energy-Only depends on shapes and sizes of the conductors and onthe type of insulating material between them24.2 Capacitors in Series and in Parallel:-Series: -Capacitors are connected one after the other by conducting wires between points a and b-Both capacitors = initially uncharged-Applying a constant positive potential difference V_ab between points a and b charges the capacitors-Capacitors have the same magnitude of charge-Their potential differences add up to the total potential difference-Equivalent capacitance:1/C_eq = 1/C_1 + 1/C_2-Parallel:-Capacitors connected in a way in which charges can reach each capacitor independently of the source-Each capacitor has the same potential V = V_ab-Charge of each capacitor depends on capacitanceEx: Q1 = C_1V-Capacitance of equivalent capacitance = C_eq = C_1 + C_224.3 Energy Storaneg in Capacitors and Electric-Field Energy:-Electric potential energy stored in a charged capacitor = amount of work required to charge itU = (1/2)QV = (1/2)CV^2-Electric energy density for any capacitor in a vacuumu = (1/2)epsilon_naught*E^224.4 Dielectrics:-Capacitance when dielectric is present = C = KC_0 = K*epsilon_naught*A/d = epsilon*(A/d)Electric field w/ dielectricsE = E_0/K