# Physics Quicksheets - DC and AC Circuits

 Direct Current Current: Current: the flow of electric charge.  Current is given by: SI units: Amp (A) = C/s *The direction of current is the direction positive charge would flow, or from high to low potential. Ohm's Law and Resistance V = IR  *can be applied to entire circuit or individual resistors. Circuits - Resistance Opposition to the flow of charge. *Resistance increases with increasing temperatures with most conductors) SI units: Ohm (Ω) = Circuit Laws Kirchoff's Laws: 1. At any junction within a circuit, the sum of current flowing into that point must equal the current leaving. 2. The sum of voltage sources equals the sum of voltage drops around a closed circuit loop. Alternating Current:   Series Circuits I = Constant Reff = R1 + R2 + R3 +...Veff = V1 + V2 + V3 + ... Parallel Circuits: V = Constant Ieff = I1 + I2 + I3 + ... Power Dissipated by Resistors SI units: Watt (W) = J/s Capacitance the ability to store charge per unit voltage. It is given by: or ε0 = 8.85 x 10-12 C2/N*m2 SI units: Farad (F) = Capacitors in Parallel:  Capacitors in Series:  Energy Stored by Capacitors  Battery Internal Resistance (r): PG 226 Dielectrics nonconducting material that increases capacitance. Cnew = kCold K = constant dependent on material Authorawc1990 ID227425 Card SetPhysics Quicksheets - DC and AC Circuits DescriptionKaplan Quicksheets Chapter 8 Updated2013-07-22T17:36:19Z Show Answers