BRIDGE CURRICULUM GUIDE ELECTRICITY
ELECTRICITY APPLIED
Technological work is enhanced by grasping basic principles of electricity, mechanics, fluid dynamics and thermodynamics. The next four sessions will introduce the applied theory and a few of the industrial applications of electricity.
The focus of today’s session is to track the flow of electricity through a common shop measuring device, the multimeter. Alternating current and direct current will also be investigated via voltage, current and resistance.
While electronics are growing more pervasive in our everyday lives, do we know the proper fundamentals about using electricity safely?
Define: current, voltage, resistance, power, open and closed circuits.
During this four-hour session you will use proper electrical safety fundamentals to:
1. Observe use of a multimeter and its components.
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HFCC - 2000 MODULE 1-1

BRIDGE CURRICULUM GUIDE ELECTRICITY
ELECTRICITY APPLIED
2. Discuss the fundamental principle of electricity, Ohm’s Law.
3. Practice use of applied shop math to solve
Ohm’s Law applications.
4. Measure alternating current and direct current with a multimeter for basic troubleshooting of open, closed and short circuits.
5. Troubleshoot for electrical problems such as a short circuit.
Observe the demonstration of the multimeter.
Pay particular attention to the scale and pointer and how the scale value changes with changes in the dial settings.
Demonstrate use of multimeter, including current, voltage and resistance measurements.
Confine resistance measurements to checking for open, closed, and short circuits.
Use different voltage and resistance values to demonstrate and discuss the relationship between the pointer and scale on an analog meter.
Lecturette:
” Voltage, the unit of measurement for voltage (EMF), and the voltage of normal household electricity.
To give this information a broader context you may want to select some full or partial terms and definitions from Delmar’s
Standard Textbook of Electricity
(pp 26-48) ..
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HFCC - 2000 MODULE 1-2

BRIDGE CURRICULUM GUIDE ELECTRICITY
ELECTRICITY APPLIED
”
Current, the unit of
measurement for current (ampere).
” Resistance, the unit of
measurement (Ohm).
” Open, closed, and short circuits.
Introduction to electricity includes information on:
___ The Coulomb
___ The Amp
___ The Electron Theory
___ The Conventional Current
Theory
___ Speed of Current
___ Basic Electrical Circuits
___ The Volt
___ The Ohm
___ The Watt
___ Other Measures of Power
___ Ohm’s Law
___ Metric Units (tie in to Math
Module #7)
In electricity the formulas P = IV and E = IR come up. Mathematically these formulas are the same as D= RT, where D equals , R equals , and T equals . This formula was used to solve the turnpike problem in Math Module 10.
During that module you probably came up with rules similar to these:
1. If you know the two variables on the right side, multiply.
2. If you know the variable on the left side and one variable on the right, divide the
In an earlier math module students learned to manipulate formulas with three variables.
This would be a good time to review and reinforce that concept by applying it to the electrical theory known as
“Ohm’s Law”. The activity will show students who may have difficulty grasping this math concept a short cut.
Instructors should demonstrate these rules by showing a few problems. Use traditional algebraic notation for substitution and solving by dividing.
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HFCC - 2000 MODULE 1-3

BRIDGE CURRICULUM GUIDE ELECTRICITY
ELECTRICITY APPLIED known value on the left by the known value on the right.
The following “Triangle Memory Trick” is a common tool used in applied math, often on the shop floor.
1. If you know R and T, cover D.
2. Since the numbers are next to each other, multiply.
3. If you know D and R, cover T.
4. Divide because the numbers are one atop another and it looks like a fractional notation for division.
Give the students pairs of numbers representing power, voltage or current and the P=IV triangle.
Now try using the triangle in a few problems given by your Instructor.
Finally, draw the triangle with the resistance formula and some other three-variable
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HFCC - 2000 MODULE 1-4

BRIDGE CURRICULUM GUIDE ELECTRICITY
ELECTRICITY APPLIED formulas that you invent like a=bc or mh=e.
How do you know which variable goes on top?
Hint: which variable is alone?
The Instructor will explain the correct use of the multimeter and the proper connection procedures.
1. Connect the multimeter to measure voltage and take voltage readings of both DC and AC circuits.
2. Connect the multimeter to measure current and take current readings of DC circuits.
3. Measure resistance on open, closed and short circuits.
Notes of Importance
- The first step in troubleshooting a problem is to identify whether or not you have voltage.
- Next, identify current flow, or the lack of it, and its level.
- A current flow that is excessive can indicate a short circuit. It will usually cause a fuse to blow.
We recommend the use of an isolation transformer for added safety in this experiment. Also, the AC voltage used should be from a low voltage power supply.
If high AC voltage is to be used, this should be done as a demonstration by the instructor.
Instructors should go between using Ohm’s Law to predict measurement values and proving readings taken by using
Ohm’s Law.
Stress the following points from pp 226-283:
- How is a multimeter connected in a circuit to measure current?
- How is a multimeter connected in a circuit to measure voltage?
- How is a multimeter used to check for an open, closed, or short circuit?
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HFCC - 2000 MODULE 1-5

BRIDGE CURRICULUM GUIDE ELECTRICITY
ELECTRICITY APPLIED
Using multimeter readouts of working and non-working electrical devices provided by the instructor, measure DC and AC voltage.
Demonstrate the multimeter by measuring voltage and current from a DC and AC source.
Measure resistance of things like the element on a toaster or a hair dryer.
SFQ Journal Entry
Summarize one activity from today’s exploration. What did you do? What did you find? What questions still remain?
Have the students read and explain the values of DC and
AC voltage. Have students handle unplugged working and non-working electrical devices with simple faults. Have students identify faults without handling the devices or their power cables. For example, use things like a bad connection inside a plug, a blown fuse, faulty switch, a short circuit in a cord, etc. Have students determine how the multimeter will read based on the faults. electromotive force
Ten terms from this unit should be provided to the communications instructor to incorporate into the vocabulary database or used for a vocabulary moment.
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HFCC - 2000 MODULE 1-6

BRIDGE CURRICULUM GUIDE ELECTRICITY
ELECTRICITY APPLIED resistance fuse circuit breaker open circuit closed circuit short circuit multimeter analog readout digital readout
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HFCC - 2000 MODULE 1-7