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Alternating Current Fundamentals
A.
Bhatia
Overview
An alternating
current (AC) is an electrical current whose magnitude and direction vary
cyclically, as opposed to direct current, whose direction remains constant. The
usual waveform of an AC power circuit is a sine wave.
Like DC, with AC circuits,
power is equal to volts x amps, but this is only true instantaneously.
Thus the power at any one moment in time is equal to the Volts at that time
multiplied by the Amps at that time. If we want to find the average power used,
we must take the average of the power at each time interval. Mathematically this
is known as Integration. The integral of a sinusoid over one full period
is zero, because there is as much time spent below zero as above it.
This course provides a basic
introduction to AC theory. The text is arranged to let you progress at your own
pace, and concepts and terms are introduced as you need them, with many detailed
examples and illustrations. This course will be extremely helpful to
individuals who are just beginning a career in electrical work, or who require a
basic knowledge of electrical principals and equipment to better their primary
responsibilities. This course is also a prerequisite for the all other
electrical training.
This 3-hr course material is based entirely on Naval Education and Training
Materials (NAVEDTRA 14173),
Electricity and Electronic Training Series;
Module-2 “Introduction to alternating current and transformers” and covers
Chapter 1, “Concepts of Alternating Current”.
The
student must take a multiple-choice quiz consisting of fifteen (15) questions at the
end of this course to obtain PDH credits.
Specific Knowledge or Skill Attained
This course teaches the
following specific knowledge and skills:
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The differences between
AC and DC voltage and current
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The advantages of AC
power transmission over DC power transmission
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The "left-hand rule" for
a conductor
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The relationship between
current and magnetism
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The methods by which AC
power can be generated
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The relationship between
frequency, period, time, and wavelength
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Compute peak-to-peak,
instantaneous, effective, and average values of voltage and current
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Compute the phase
difference between sine waves
Course
Click on the following
PDF attachment and review the document prior to taking
a quiz for credit.
Concepts of Alternating Current (335 KB)
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To obtain PDH credits for this course, you will need to take a quiz for
credit. Click on the link below.
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