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Introduction to Capacitance
A.
Bhatia
Overview
Capacitance is the
property of an electric conductor that characterizes
its ability to store an electric charge. An electronic device called a capacitor
is designed to provide capacitance in an electric circuit by providing a means
for storing energy in an electric field between two conducting bodies. A
capacitor in its simplest form consists of two conducting plates separated by an
insulating layer called a dielectric. When a capacitor is connected in a circuit
across a voltage source, the voltage forces electrons onto the surface of one
plate and pulls electrons off the surface of the other plate resulting in a
potential difference between the plates.
Capacitance
is directly proportional to the electrostatic force field between the plates.
This field is stronger when the plates are closer together. Therefore, as the
distance between the plates decreases, capacitance increases. Also capacitance
is directly proportional to the plate area. Larger plates provide greater
capacity to store electric charge. Therefore, as the area of the plates
increase, capacitance increases.
This 3-hr course provides
a basic overview of capacitance theory and is based
entirely on Naval Education and Training
Materials (NAVEDTRA 14174),
Electricity and Electronic Training Series;
Module-2, Chapter 3,
titled “Capacitance”.
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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Definition of the terms
"capacitor" and "capacitance"
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Four characteristics of
electrostatic lines of force
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Three factors that
affect the value of capacitance
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Two types of power
losses associated with capacitors
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Definition of "working
voltage" of a capacitor, and how to compute the working voltage of a capacitor
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What happens to the
electrons in a capacitor when the capacitor is charging and when it is
discharging
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The relationship between
voltage and time in an RC circuit when the circuit is charging and discharging
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How to calculate the
value of total capacitance in a circuit containing capacitors of known value
in series and parallel circuits
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The difference between
different types of capacitors
Course
Click on the following
PDF attachment and review the document prior to taking
a quiz for credit.
Capacitance (457 KB)
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