University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Lecture19
Chapter 24: Impedance Networks
241 Loop Equations
For AC circuits, we restate Kirchhoffs voltage law (KVL) using phasor
quantities:
In any complete (closedloop) AC circuit, the phasor sum of the voltage
drops must equal the phasor sum of volt
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Midterm
Average: 56
Maximum: 100
Minimum: 10
Superposition Principle
Superposition Principle
To find a voltage or current in a linear
circuit containing N independent sources,
one can consider the effect of sources one
at a time by zeroing the other so
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Page 1 of 11
Version A
Solutions
1.
Find the voltages at nodes a and b in the figure below using nodal analysis.
Va = _ V and Vb = _ V (round to four decimal places)
Solution:
At node a,
6 Va
30
=
Va
10
+
Va Vb
6
360 = 540Va 300Vb
At node b,
Va Vb
14 Vb
1
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
ELEE 2790U:
Electric Circuits
Instructor: Lixuan Lu
Office: ERC4084
Phone: 9057218668 ext. 5526
Email: lixuan.lu@uoit.ca
Office hour: Wednesday 2:30pm3:30pm
Course Information
Lecture previews, marked lectures
and tutorial material can be found
from t
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
ELEE 2790U:
Electric Circuits
Instructor: Lixuan Lu
Office: ERC4084
Phone: 9057218668 ext. 5526
Email: lixuan.lu@uoit.ca
Office hour: Wednesday 2:30pm3:30pm
Course Information
Lecture previews, marked lectures
and tutorial material can be found
from t
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
TEMPLATE 8D
Revised July 14, 2014
[V.K.SOOD]
[Course Number]: [Electric Circuits]
Course outline for [Fall, 2015]
1. Course Details & Important Dates*
Term
Course Type
Day
Fall
Lecture
Time
Tuesday
Thursday
9.40 11.00
8.409.30
Location
CRN #
Classes Sta
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Lecture20
PowerFactor
2
ComplexPower
3
ComplexPower
4
Example
5
Example
6
Example
7
RealPowertoComplexLoad
8
Example
9
Example
10
Example
11
Example
12
Example
13
14
PowerCorrection
15
Example
16
Example
17
Example
18
Example
19
Example
20
Example
21
Exam
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Lecture19
Chapter 24: Impedance Networks
241 Loop Equations
For AC circuits, we restate Kirchhoffs voltage law (KVL) using phasor
quantities:
In any complete (closedloop) AC circuit, the phasor sum of the voltage
drops must equal the phasor sum of volt
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Lecture13
Chapter 12: Capacitance
121 Electric Fields
An electric field is that region in which a charge is acted upon by an
electric force.
The strength (intensity) of an electric field is the force the field exerts
on a unit of charge.
The symbol fo
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Lecture16
Chapter 18: Alternating Current
181 A Simple Generator
A generator uses electromagnetic induction to produce a potential
difference.
As a loop of conductor rotates within a stationary magnetic field,
electrical connection is maintained throug
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Lecture14
Chapter 14: Magnetism
141 Magnetic Fields
A magnetic field is that region in which a magnetic material is acted
upon by a magnetic force.
The strength and direction is represented by magnetic lines of force
(or magnetic flux lines).
These li
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Lecture15
Chapter 16: Inductance
161 Electromagnetic Induction
1. The process of inducing voltage across a
solenoid by moving a magnet through it. (the
magnetic field was moved while the electric
conductor remains stationary).
2. The generation of a volt
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Lecture18
Chapter 22
Power in AlternatingCurrent
Circuits
221 Power in a Resistor
All equations derived for DC circuits apply also to AC circuits.
Therefore,
p = vi
(221)
v is positive when i is positive and negative when i is negative.
instantaneou
University of Ontario Institute of Technology (UOIT)
ELEE 2790

Fall 2015
Norton Theorem
An active network (i.e. a network that
contains independent sources) can be
replaced by the socalled Norton
circuit. This circuit consists of an ideal
current source
in parallel with an
equivalent resistance
.
The Norton resistor is obta