This document provides an overview of basic circuit laws and terms. It defines common circuit elements like nodes, branches, loops, and meshes. It then explains Ohm's Law, which states that voltage is directly proportional to current. Kirchhoff's Laws are also introduced, including Kirchhoff's Current Law (KCL) and Kirchhoff's Voltage Law (KVL). KCL states that the sum of currents at a junction is 0, and KVL states that the sum of voltages around a loop is 0. Examples of series and parallel resistor calculations are provided to demonstrate voltage and current division.

1. Lecture 2
Basic Circuit Laws

2. Common DC Circuit Theory Terms:
• Circuit – A circuit is a closed loop conducting path in which an electrical
current flows.
• Path – A single line of connecting elements or sources.
• Node – A node is a point of connection between two or more branches
• Branch – A branch is a single element such as a voltage source or a resistor
• Loop – A loop is a simple closed path in a circuit in which no circuit
element or node is encountered more than once.
• Mesh – A mesh is a single open loop that does not have a closed path.
There are no components inside a mesh.

3. Example

4. Basic Circuit Laws
• Ohm’s Law - A linear relationship between the voltage and the current in an
electrical circuit.
• Kirchhoffs Law - Relation of values of currents that flow through a junction
point and voltages in a an electrical circuit loop, in an
electrical circuit.
1. Kirchhoffs Current Law(KCL)
2. Kirchhoffs Voltage Law(KVL)
Kirchhoff
Ohm

5. Ohm’s Law
• Ohm’s law states that the voltage(V) across a resistor is directly
proportional to the current(i) flowing through the resistor
V ᾳ I
• The proportionality constant is Resistance
V=IR
Note: S.C and O.C
resistance

6. Kirchhoff's Current Law (KCL)
• The sum of all currents that enter an electrical circuit junction is 0. The
currents enter the junction have positive sign and the currents that leave
the junction have a negative sign

7. Kirchhoff's Voltage Law(KVL)
• The sum of all voltages or potential differences in an electrical circuit loop
is 0.

8. Examples problem

9. Voltage and Current Division Rule
• Series Resistor and Voltage Division
• Parallel Resistance and Current Division

10. Problems

11. • Thank u