L5: Solving Complex Resistive Circuits

Question 1

What is Kirchhoff’s Current Law (KCL)

Answer 1

Question 2

What is Kirchhoff’s Voltage Law (KVL)

Answer 2

Question 3

Example Problem using Method of Branch Currents:
Given an electric circuit with known resistance values, where series/parallel reductions can not be applied, find the currents and voltage drops through all of the resistors?

Answer 3

1. Assume and indicate current directions at all branch points
2. Mark the voltage polarity consistent with assumed current directions for all resistors
3. Identify loops and write loop equations for voltage drops using KVL
4. Voltages are specified as IR drops, and solve the set of simultaneous equations to find the unknown branch currents
5. Use Ohm’s Law to calculate voltages drops across individual resistors

Question 4

Example Problem using Node-Voltage Analysis:

Given an electric circuit with known resistance values, where series/parallel reductions can not be applied, find the currents and voltage drops through all of the resistors?

Answer 4

1. Assume and indicate current directions at all branch points
2. Mark the voltage polarity consistent with assumed current directions for all resistors
3. Identify principal nodes (i.e a common connection between three of more components) and write node equations for currents in and out of the node using KCL.
4. Express currents as V/R so that the equations of currents can be solved to find a node voltage
5. Use Ohm’s Law to calculate current across individual resistors

Question 5

What happens when using Node Equations compared to Loop Equations

Answer 5

Question 6

Answer 6

Question 7

Answer 7