# EE 304 - CH1

 The flashcards below were created by user jcfroel on FreezingBlue Flashcards. Passive sign convention An assumption of: the sign of the current RELATIVE to the voltage for passive circuit elements. ASSUME: positive current enters the node at the higher voltage ESSENTIALLY:  You can assume (arbitrarily) EITHER the voltage polarity, OR the current direction.  This assumption dictates the assumed direction of the other parameter.  These assumptions provide REFERENCE voltage polarities and current directions. 3 Steps to assign passive sign convention.  (and what not to do) DON'T try to figure out the "correct" voltage polarities or current directions before performing the analysis. 1.  Arbitrarily assign EITHER the assumed voltage polarity OR the current direction. 2.  Label the other characteristic for the passive circuit element so that they agree with the passive sign convention.3.  Perform the analysis using the assumed signs!  Negative values indicate that the assumption you made was wrong, so switch up the assumed direction of either the current or of the voltage polarity. How to provided voltage sources affect the choice of the passive sign convention? they dont!!!!!!!!!!!!!!!! Charge Charge (q) is the basic quantity in circuit analysis Unit:  Coulombs.  1 Coulomb = -6.24 10^18 electrons Current Current (i) is the rate of change of charge with time: UNITS: Amperes (coulombs/second) i = dq/dt If you're sitting at some point in you're circuit and watching electrons go by, the rate at which they're going by gives you the current! Voltage Voltage (v):  Voltage quantifies the change in energy of a unit charge at two different physical locations. v = dW/dq Units:  Volts (V) => Joules/coulomb Power Power is the rate of change of energy with time UNITS: watts P = dW/dt = dW/dq x dq/dt = (v)(i) [voltage times current] Passive Circuit element Total energy delivered to the circuit element by the rest of the circuit is non-negative. Passive element can STORE or DISSIPATE energy but it cannot CREATE energy. Active Circuit element Active circuit elements can supply energy to the circuit from external sources. Giga, Mega, Kilo Giga = 10^9 Mega = 10^6 Kilo = 10^3 Micro, Nano, Pico Micro = 10^-6 Nano = 10^-9 pico = 10^-12 Authorjcfroel ID255085 Card SetEE 304 - CH1 DescriptionPassive sign convention, basic parameters Updated2014-01-04T14:58:02Z Show Answers