1. Electrical Circuit An consists of a power source, conductors, and lo
2. simple curcuit A consists of only one energy source, one conduct
and one load.
3. series curcuit A simple has at least two loads. The current flows alon
a single path and the components are located one after another
along this path
4. parallel curcuit A simple , the voltage applied to each branch is the
same
5. direction of currentwhat do arrows indicate
6. electron flow Inside a DC power source (such as a battery) the electrons travel from
the
positive terminal to the negative. Electrons traveling outside of the
power source (a circuit) electrons travel from the negative to the positive
terminal.
7. continuity The continuous ettective contact with all parts of an electrical circuit
give
it a high conductance (low resistance).
8. direct current and al- What are two types of electric current?
ternating current
9. power source In any completed circuit, it takes a force to push the electrons throug
the , conductor, and load. The two types of force to
push the electrons of electric current are direct current (DC) and
alternating current(AC).
10. load 1) Power output such as a power
plant.
(2) A device to which power is delivered.
(3) The demand upon the operating resource of a
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, CSLB Contractor B Exam (electrical) Study Test.
system such as a telephone exchange system or circuit of
garden lights.
11. direct current
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The polarity from power sources never changes; that
is, the current flows out of the negative terminal of the power
source in the same direction
12. alternating curent power sources produce a voltage and current that has a consta
change
in polarity and magnitude at a constant frequency, back and forth in
a conductor. flow is produced by a generator
or an alternator.
13. frequency The rate of flow reversal is called
14. 60 cycles per Nearly all AC power systems in U.S.A. operate at a frequency of
second
(60 Hz)
15. AC waveforms When an alternator produces AC voltage, the voltage switches polar
over
time, but does so in a very particular manner. When graphed over
time, the "wave" traced by this voltage of alternating polarity from
an alternator takes on a distinct shape, known as a sine wave.
16. conductance is the property of metal that permits current to flow
17. 1/resistance =conductance
18. resistance is the opposite of conductance. It is the property that o
poses the flow of electric current and the friction opposition to
the flow of electrons
19. impedance is the total opposition to current flow in an ac circuit,
is measured in ohms
20. voltage Electron pressure is called electromotive force. The electromotive fo
liter-
ally means the force that moves electrons. The unit of measure of
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this force is the
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