1. Electric Circuits I (EELE 2310)

2. Electric Power Engineering site.iugaza.edu.ps/ajasser
Assad Abu-Jasser, PhD
Electric Power Engineering
site.iugaza.edu.ps/ajasser

3. Chapter Two
Circuit Elements

4. Electric Sources Voltage and Current Sources
Electrical Source is a device that is capable of converting nonelectric energy to electric energy and vice versa
An Ideal Voltage Source is a circuit element that maintains a prescribed voltage across its terminals regardless of the current flowing in those terminals
An Ideal Current Source is a circuit element that maintains a prescribed current through its terminals regardless of the voltage across those terminals

5. Voltage and Current Sources Independent Sources
An Independent Source establishes a voltage or current in a circuit without relying on voltages or currents elsewhere in the circuit

6. Voltage and Current Sources Dependent Sources
A dependent Source (Controlled Source) establishes a voltage or current whose value depends on the value of a voltage or a current elsewhere in the circuit
μ, ρ, α, and β are multiplying constants
Active Elements capable of generating electric energy Passive Elements cannot generate electric energy

7. Example 2.1 Valid Invalid Valid Valid Invalid
Using the definition of the ideal independent voltage and current sources, state which interconnections in the following figures are permissible and which violate the constraints imposed by the ideal sources
Valid
Invalid
Valid
Valid
Invalid

8. Example 2.2 Invalid Valid Valid Invalid
Using the definition of the ideal independent and dependent sources, state which interconnections in the following figures are valid and which violate the constraints imposed by the ideal sources
Invalid
Valid
Valid
Invalid

9. Electrical Resistance Ohm’s Law

10. Example 2.3
In each of the following circuits υ or i is not known. (a) Calculate the value of υ or i, (b) Determine the power dissipated in each resistor.
8 V
-20 V
10 A
-2 A

11. Example 2.4 Constructing A Circuit Model

12. Example 2.5
The voltage and the current are measured at the terminals of the device in the figure shown and the values are tabulated as given. Construct a circuit model of the device inside the box.

13. Kirchhoff’s Laws Kirchhoff’s Current Law
7 Unknowns
The algebraic sum of all currents at any node in a circuit equals zero

14. Kirchhoff’s Laws Kirchhoff’s Voltage Law
The algebraic sum of all voltages around any closed path in a circuit equals zero

15. Example 2.6
Sum the currents at each node in the circuit shown. Note that there is no connection dot (●) in the center of the diagram.

16. Example 2.7
Sum the voltages around each designated path in the circuit shown.

17. Example 2.8
Use Kirchhoff’s laws and Ohm’s law to find io in the circuit shown and test the solution for io by verifying that the total power generated equals the total power dissipated.

18. Example 2.9
The terminal voltage and the terminal current were measured on the device shown in the figure shown and the values are tabulated. (a) construct a circuit model of the device inside the box, (b) using the circuit model, predict the power this device will deliver to a 10 Ω resistor.

19. Analysis of Circuits Containing Dependent Sources

20. Example 2.10
Use Kirchhoff’s laws and Ohm’s law to find the voltage υo in the circuit shown and test the solution by verifying that the total power developed equals the total power dissipated.

21. Practical Perspective Electrical Safety

22. End of
Chapter Two