Series & Parallel Circuits Chapter 23

23.1 Simple Circuits Water moving down a mountain river The water goes down the mountain because of a difference in gravitational potential energy The water represents electrical current The electric current moves through a circuit because of a difference in electric potential

Series Circuits A circuit that has only one path for the current to flow Remember that charge cannot be created or destroyed and current is amount charge moving per second The potential difference is shared by each device in the circuit. Also call voltage drop because as the current passes through each device uses some of the total voltage until it is all used up

I & R in a series circuit In an electric circuit, the increase in voltage provided by the energy source (battery), Vsource, is equal to the sum of the voltage drop across the devices Vsource=VA+VB+…

Equivalent Resistance in a Series Circuit The equivalent resistance is the one resistor that could replace all the resistors of the circuit and keep the same current In a series circuit the resistance adds R=RA+RB+… The equivalent resistance is greater than any individual resistor

Voltage drop in a Series Circuit As current moves through any circuit the net change in potential must equal zero Gains in the energy source and loses as current passes through the resistors

Voltage Divider Used to change a higher voltage to a lower voltage as the current passes through a device. Source is 12 V and device required 9 V A resistor is placed in series with the device to use the extra 3 V

Parallel Circuits More than one path for the current to flow Similar to a mountain river and breaks off into three different rivers. All three have the same starting and ending gravitational potential energy The total river current has to be split into three separate paths

Resistors in a Parallel Circuit V=VA=VB… I=IA+IB+… Equivalent resistance for a parallel circuit