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1. Didactic Reflection
1.1 Curriculum Analysis
The Module is DC circuits analysis to give the trainees basic knowledge of electrostatic,
batteries, and fundamentals of DC current. Also covered are analysis of DC circuits,
electromagnetism, and magnetic circuits.
Electrical Power
& Machinery
& Equipment
Department:
Electrical Technology
Specialization:
Module Name:
DC circuits
Course code:
ELT 106
Prerequisites:
None
Trimester
2
The Module contains an explanation of
electrostatics laws, batteries, DC circuit analysis,
electromagnetism and magnetic circuits. The
course contents include: capacitors, Ohm's law,
Kirchhoff's laws, series & parallel circuits, power,
and DC bridges.
Credit
Hours
Conta
ct
Hours
(h/w)
3
L
P
3
0
T
1
Students are having passed through this course the students will study Electrical
Circuits- 2
1
Before the lessen:
Module 1 -Electrostatics:
Unit 1 Electric charge:
 Electric charge
 Coulomb's law
 Force between two charges
 Electric field
 Electric potential
 Potential difference
Unit 2 Capacitors:
 Capacitance of an isolated ball
 Capacitance of an earthed ball capacitor
 Capacitance of a parallel plate capacitor
 Series and parallel connections of capacitors
 Energy stored in capacitors
Module 2 -DC circuits analysis:
Unit 1 Electrical Quantities:
 Quantity of charge
 Current and current intensity
 DC voltage and current
 Resistance and resistors
 Ohm's law
After the lessen :
Unit 2 -Methods of connecting resistors:
 Series connection of resistors
 Parallel connection of resistors
 Series-parallel connection of resistors
 Calculation of resistances connected in series-parallel
Connections
Unit 3-Kirchhoff's laws:
 Kirchhoff's current laws.
 Kirchhoff's voltage laws.
2
1.2 Content Analysis
The TVTC Curriculum RCT:
What is electrical circuits?
It is a closed path for the electrical current.
The main definition of electrical circuits:
•
The voltage is the difference in electrical potential between two points in a circuit.
•
The current is what flows on a wire or conductor like water flowing down a river.
•
The resistor :determines how much current will flow through a component.
Ohm's law:
I: current (A)
V: voltage (V)
R: resistor (Ω)
For example:
What is the current when V=20v and R=10KΩ ?
= 20V/10KΩ
= 2mA
POWER in electrical circuits:
It is the amount of work performed per unit time. Denoted by the symbol P
W: work
t: time
There are three laws of power:
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Web- Research : Source:(Electrical Circuits Book ,2008 and page 88-93)
Ohm's law states that the current through a conductor between two points is directly
proportional to the potential difference across the two points. Introducing the constant of
proportionality, the resistance, one arrives at the usual mathematical equation that
describes this relationship:
where I is the current through the conductor in units of amperes, V is the potential
difference measured across the conductor in units of volts, and R is the resistance of the
conductor in units of ohms. More specifically, Ohm's law states that the R in this relation
is constant, independent of the current.
In circuit analysis, three equivalent expressions of Ohm's law are used interchangeably:
Each equation is quoted by some sources as the defining relationship of Ohm's law, or all
three are quoted, or derived from a proportional form, or even just the two that do not
correspond to Ohm's original statement may sometimes be given.
The interchangeability of the equation may be represented by a triangle, where V
(voltage) is placed on the top section, the I (current) is placed to the left section, and the
R (resistance) is placed to the right. The line that divides the left and right sections
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indicate multiplication, and the divider between the top and bottom sections indicates
division.
Ohm's Law can be used to solve simple circuits. A complete circuit is one which is a closed loop.
It contains at least one source of voltage (thus providing an increase of potential energy), and at
least one potential drop i.e., a place where potential energy decreases. The sum of the voltages
around a complete circuit is zero.
4. An increase of potential energy in a circuit causes a charge to move from a lower to a higher
potential (ie. voltage). Note the difference between potential energy and potential.
Because of the electrostatic force, which tries to move a positive charge from a higher to a lower
potential, there must be another 'force' to move charge from a lower potential to a higher inside
the battery. This so-called force is called the electromotive force, or emf. The SI unit for the emf
is a volt (and thus this is not really a force, despite its name). We will use a script E, the symbol ,
to represent the EMF.
A decrease of potential energy can occur by various means. For example, heat lost in a circuit
due to some electrical resistance could be one source of energy drop.
Because energy is conserved, the potential difference across an emf must be equal to the
potential difference across the rest of the circuit. That is, Ohm's Law will be satisfied:
=IR
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POWER
Power (symbol: P) is defined as the amount of energy consumed per unit time. In the MKS
system, the unit of power is the joule per second (J/s), known as the watt. For example, the rate
at which a light bulb converts electrical energy into heat and light is measured in watts—the
more wattage, the more power, or equivalently the more electrical energy is used per unit time.
Energy transfer can be used to do work, so power is also the rate at which this work is
performed. The same amount of work is done when carrying a load up a flight of stairs whether
the person carrying it walks or runs, but more power is expended during the running because
the work is done in a shorter amount of time. The output power of an electric motor is the
product of the torque the motor generates and the angular velocity of its output shaft. The power
expended to move a vehicle is the product of the traction force of the wheels and the velocity of
the vehicle.
The instantaneous electrical power P delivered to a component is given by
where
P(t) is the instantaneous power, measured in watts (joules per second)
V(t) is the potential difference (or voltage drop) across the component, measured in volts
I(t) is the current through it, measured in amperes
If the component is a resistor with time-invariant voltage to current ratio, then:
where
is the resistance, measured in ohms.
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Horsepower (hp) is the name of several units of measurement of power, the rate at which work
is done. The most common conversion factor, especially for electrical power, is 1 hp = 746
watts.
The content
Step-1
What is electrical circuits?
It is a closed path for the electrical current.
The main definition of electrical circuits:
•

The voltage is the difference in electrical potential
between two points in a circuit.
•
The current is what flows on a wire or conductor like water flowing down a river.
•
The resistor :determines how much current will flow through a component.
Step-2
Ohm's law:
I: current (A)
V: voltage (V)
R: resistor (Ω)
Step-3
For example about Ohm's law:
What is the current when V=20v and R=10KΩ ?
= 20V/10KΩ
I = 2mA
7
Step-3
Electrical resistance:
Step-4
POWER in electrical circuits:
It is the amount of work performed per unit time. Denoted by the symbol P
There are three laws of power:
Step-5
For example:
What is the power when V=120v and I=5A ?
P=I*V
=120*5
P = 600w
P= 0.804hp.
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1.3 Didactic Analysis
3.1 Trainees
There are 20 trainees in class and each trainee has at the General Certificate of Secondary
Education in the natural sciences. Most of trainees are from Riyadh and the range of age is
between 19-23. An experience in the electrical power can not be expected.
3.2 Classroom:
Trainees to perform the lesson in an appropriate from the following equipment will be necessary:
1- Projector.
2- Whiteboard.
3- Computer.
4- Power point.
5- Test board.
6- Loudspeaker.
3.3 college:
The lesson is started for 13 April 2014, 8:50 a.m in room 12F, building 20.
Using In step1 classroom conversation because:
 To discussion about the example.
 To communicate with the trainees.
Using video in this step because:
 To take their attention.
 To make the trainees focus.
 To make the lesson easy.
Using feedback control because:
 To know if the trainees understand from video.
 To listen for trainees's opinion.
Using experiment in this step because:

To mix the theory and practical together.

To clarification for trainees.
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Using lecture in step 2 because:


To give them information clearly.
To learn them on the right way.
Using individual work in the worksheet because:




To know where the trainees of this lesson.
To individually think and solve problems.
To assess the trainees.
To motivate the trainees to work.
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2 Lesson Plan
II. Objectives
General Objectives:
The Trainees:
1. will increase their social competencies by participating
Specific Learning Objectives:
The Trainees will be able to:
1. explain the ohm's law (Reorganization).
2. explain the voltage and current and resistor (Reorganization).
3. calculate the voltage, the current and resistor by using the formula of ohm's law
(Reorganization).
4. Learn how to measuring the current in the circuit.
III. Overview of the Intended Process
Opening / Entrance / Motivation
Time
Methodology
Expected Trainer-action
The trainer welcomes the
trainees and takes the
attendance.
Present example from real
life that explains to the
circuit.
definition for voltage,
current and resistors.
Media
Expected Trainee-action
_
Minutes
_
Classroom
_
conversation
_
2 min
Projector
Handout
5 min
Slid 2+3
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Body (Information / Elaboration)
Expected Traineraction
Presentation video
(Electricity - Ohm's
Law) ohm's law
Time
Methodology
Media
Minutes
Expected Trainee-action
Presentation
-
Projector
Video
5
Slid 4
Feedback
Control Question
Experiment on the
testboard to sere
Hands up an
experience to
trainees
Explanation of the
formula of ohm's law
and introduction to
symbols and units
and relationship
between current and
voltage.
Control
-
Experiment
Testboard
-
2
5 min
Group work
Worksheet
Projector
-.
Classroom
Whiteboard
conversation
5 min
Handout
Slide 5+6
Projector
Calculation of the
voltage , current and
resistor.
The trainer gives
worksheet to the
trainees.
-
Classroom
conversation
Whiteboard
4 min
Handout
Slide7+8
The trainees answer and select
three of them to answer on
whiteboard
Individual
Work
Worksheet
5 min
12
Projector
Calculation of the
resistors and gives
them example.
-
Classroom Whiteboard
4 min
conversation
Slide 9+10
Projector
Explanation of the
laws of power
-
Lecture
Handout
4 min
Slide 11
Calculation of the law
power.
Lecture
Projector
Classroom
handout
conversation
Slide 12
-
4 min
Close (Reflection, Exercises, Homework, Feedback)
Expected Trainer-action
Expected Trainee-action
Time
Methodology
Media
Minutes
Individual
The trainer gives the
trainees worksheet
The trainees answer the
questions.
5 min
Worksheet
Work
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4 : list of attached teaching material We will to use :











Power point .
Whiteboard .
Testboard .
Pen for whiteboard .
Power supply .
Wires .
Voltmeter .
Resistor .
Worksheet for the experiment .
Handout for the theory .
Projector and computer .
5 References




Electrical Technology, Edward Hughes
Introductory Circuit Analysis, Robert L. Boylestad, 2000
Fundamentals of Electric Circuits, Charles K. Alexander, N. O. Sadiaka,
2000
Electric Circuits, Joseph Edminister, Mahmood Nahoi, 1997

http://en.wikipedia.org/wiki/Ohm's_law

http://en.wikipedia.org/wiki/Power_(physics)

Electrical Circuits Book ,2008 and page 88-93.

Principles of Electric circuits, Thomas L. Floyd, 1999 page 76-99.
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