Electrical Engineering for Civil Engineer Dr. Basim Zafar Spring 2013 EE for CE Course Outlines MID...

Electrical Engineering for Civil Engineer Dr. Basim Zafar Spring 2013

EE for CE Course Outlines

MID TERM I

Dr. Basim Zafar

Electrical Engineering for Civil Engineer Dr. Basim Zafar Spring 2013 Slide 2

EE for CE - MID TERM I

1. Frequency.2. Resistance, Capacitor & Inductors in Parallel & Series.3. Ohm’s Law.4. Two special resistor values (Open & Short Circuit).5. Electric Power Calculator6. Kirchhoff’s Current & Voltage Law7. Voltage & Current Divider8. Circuit Analysis using KVL & KCL.9. Linearity and Superposition10. Thévenin’s Theorem 11. Source Transformations


1. Frequency

• Frequency = Number of cycles per second

voltvolt

time

time

Tf

1Unit : Hertz

a. Calculate the frequency of a signalb. Draw a signal with a certain frequency.


2. Resistance, Capacitor & Inductors in Parallel & Series.

• Calculate Resistance, Capacitor & Inductors in Parallel & Series combinations.

• Capacitors: Passive electronic component consisting of a pair of conductors separated by a dielectric (insulator). Measured in Farad (F)

– Uses: to block DC, to filter noise, to smooth power supplies, to tune radio channels & in memories.

• Inductors: Passive electrical component that can store energy in a magnetic field created by the electric current passing through it. Measured in Henry (H)

• Uses: Resists (reacts) AC current with delay– no effect when DC is used


3. Ohm’s Law.

• Ohm’s Law: The voltage across a resistor is directly proportional to the current moving through the resistor

• V = I


4. Two special resistor values (Open & Short Circuit).

Circuit

Short

Circuit

Open

0v

0i

0R R


5. Electric Power Calculator

• Power is the time rate of change of energy• Unit: watts (W)• P=VI = =


6. Kirchhoff’s Current & Voltage Law

• Kirchhoff’s Current Law : “The sum of the current entering a node equal to the sum of the currents leaving.”

• Kirchhoff’s Voltage Law : “Sum of the voltage drops around a circuit equal zero.”


7. Voltage & Current Divider

21

11 RR

Rvv s

21

22 RR

Rvv s

21

21 RR

RII T

21

12 RR

RII T


8. Circuit Analysis using KVL & KCL.

• To solve for all currents in more than one source circuit:

1. Count nodes minus one (possible ground)2. Mark a current for each branch (name and

direction)3. Write KCL equations for each node4. Count the loops5. Write the KVL equations for each loop6. Solve for all unknowns


9. Linearity and SuperpositionLinearity procedure:

1. Give to Vo any arbitrary value (e.g., V’out =1 )

2. Compute the resulting source value and call it V’_s

3. Use linearity. kkVkVVV outSoutS ,''''

Circuit with currentsource set to zero(OPEN)

1LI

1LV

Circuit with voltage sourceset to zero (SHORT CIRCUITED)

2LI

2LV

SOURCE SUPERPOSITION

= +

2121LLLLLL VVVIII


10. Thévenin’s Theorem • Thevenin's Theorem is a way to reduce a network to an equivalent

circuit composed of a single voltage source and a series resistance.

Steps to follow for Thevenin's Theorem:• (1) Find the by removing the load resistor from the original circuit

and calculating voltage across the open connection points.

• (2) Find the by removing all sources in the original circuit (voltage

sources shorted and current sources open) and calculating

• (3) Draw the Thevenin equivalent circuit

Thévenin Equivalent Circuit

VTh

RTh

Resistive Circuit


11. Source Transformations

Electrical Engineering for Civil Engineer Dr. Basim Zafar Spring 2013 EE for CE Course Outlines MID...

Documents

Transcript of Electrical Engineering for Civil Engineer Dr. Basim Zafar Spring 2013 EE for CE Course Outlines MID...