1. ECE 201 Circuit Theory I1 Resistors in Series Resistors connected at a single node Current through each resistor is the same

2. ECE 201 Circuit Theory I2 Identify the current in each Resistor Apply KCL at each node a b c d e f g

3. ECE 201 Circuit Theory I3 Redraw using a single current

4. ECE 201 Circuit Theory I4 To solve for the current, write KVL

5. ECE 201 Circuit Theory I5 Simplified version of the circuit

6. ECE 201 Circuit Theory I6 From a “black box” point of view These circuits are “equivalent” Same current drawn from the source

7. ECE 201 Circuit Theory I7 Summary Resistors in series have the same current The resistors can be replaced by an “equivalent” resistance equal to the sum of the individual resistors The “equivalent” resistance is larger than the largest of the individual resistors