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33 Cards in this Set
- Front
- Back
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describe relay core
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non-moveable
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describe solenoid core
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moveable core
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rheostat changes what?
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current
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potentiometer changes what?
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voltage change
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where do free electrons orbit?
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outer ring
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how many free electrons does a conductor have in the outer valance ring?
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1-3
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how many free electrons does an insulator have in its outer ring?
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5-8
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what is an unbalanced atom called?
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ion
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define semi-conductor?.. how many electrons in outer valence orbit?
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does not insulate or conduct, electrons are stable and do not want to move. Exactly 4 electrons in valence orbit
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Free electrons and conductor, semi-conductor,insulator
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C 3
S 4 I 5 |
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current flow theory: name both and describe..
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electron flow: neg to positive
conventional: pos to negative |
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define voltage:
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is the pressure forcing electrons through conductor.
- also called EMF |
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a voltmeter measures voltage potential when connected to a circuit how?
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across- parallel to the circui
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define current:
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is the quantity or flow rate of electrons moving past a point within one second
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a voltmeter measures quantity of current flow ( amperage) in a circuit when connected how?
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in series
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connect a volt meter when?
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when no voltage is applied
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name and describe 5 factors of resistance.
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LENGTH of conductor
DIAMETER of conductor TEMP of conductor PHYSICAL CONDITION TYPE OF MATERIAL |
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can static electricity perform work?
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no
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1 hp= ? watts
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746
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define:
ferromagnetic |
retains magnetism
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define:
permeability |
scale rates ease of flux penetration, and ability to magnetize
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define:
paramagnetic |
+1 on scale, and magnetism must be induced
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define:
diamagnetic |
repulsion of flux
(gold, lead, silver) |
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define:
reluctance |
a measure of opposition to the acceptance of flux lines
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electromagnetic force is proportional to what?
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proportional to # of turns in the coil and the strength of the current flowing through the coil
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components of a potentiometer circuit (3 main)
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reference, signal and the ground
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rheostat has how many terminals?
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2
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potentiometer has how many terminals?
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3
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6 sources of electricity
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friction,heat,light,pressure,chemicals,mechanical
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where can u find the color codes of resistors?
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ac 65-9 chart on page 242
ac 43.13 ? |
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what is always the output on a rheostat and pontiometer?
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wiper
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2 circuits in a relay or solenoid
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control (coil)
distributor (contacts) |
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can static electricity perform work?
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no
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