Voltage, Current and Resistance (chap 2) Flashcards
what instrument is used to measure current
Ammeter
the unit of electrical current
Ampere (A)
the smallest particle of an element possessing the unique characteristics of that element
Atom
what is an electrical property of matter that exists because of an excess or deficiency of electrons
Charge
what symbol represents charge
Q
the unit of electrical charge is expressed in
Coulomb (C)
what is an interconnection of electrical components designed to produce a desired result
Circuit
what is a resettable protective device used for interrupting excessive current in an electric circuit
Circuit Breaker
what is a circuit with a complete path
Closed Circuit
what is the ability of a circuit to allow current to flow
Conductance (G)
copper is an example of a ?
Conductor
the rate of flow of charge
Current
what is DMM
Digital multi-meter
this particle is negatively charged
Electrons
what is a valence electron that has broken away from its parent atom and is free to move from atom to atom within the atomic structure of a material
Free electron
this type of dc voltage source converts electrochemical energy from an external source into dc voltage
Fuel cell
what is a protective device that burns open when there is excessive current in a circuit
Fuse
the common or reference point in a circuit
Ground
a material that does not allow current under normal conditions
Insulator
what is an element (resistor or other component) connected across the output terminals of a circuit that draws current from that sources and upon which work is done
Load
the unit of resistance
Ohm
what instrument is used to measure resistance
Ohmmeter
a circuit in which there is not a complete patch
Open Circuit
a three terminal variable resistor used to control voltage
Potentiometer
what is the opposition to current
Resistance
an electrical component designed specifically to have a certain amount of resistance
Resistor
a two terminal variable resistor used to control current
Rheostat
a material that has conductance value between that of a conductor and a insulator
Semiconductor
what unit is conductance
Siemens (S)
an electrical or electronic device for opening and closing a current path
Switch
what unit is voltage or electromotive force
Volt (V)
what is the amount of energy per charge available to move electrons from one point to another in an electric circuit
Voltage
what device produces a constant voltage for a varying load
Voltage source
what is used to measure voltage
Voltmeter
what particles are found in the nucleus
electrons
protons
neutrons
what are the three materials used in electrons
conductors
semiconductors
insulators
what is a atom with a net positive charge
positive ion
what is a atom with a negative charge
negative ion
name 7 dc voltage source
batteries fuel cells solar cells generators power supply thermocouples piezoelectric sensors
convert chemical energy directly into electrical energy
batteries
converts light energy directly into electrical energy
solar cells
converts mechanical energy into electrical energy
generators
convers ac voltage from the wall outlet into a constant dc voltage
the power supply
this thermoelectric dc voltage source is used to sense temperature
thermocouple
what is the formula for Conductance (G)
G = 1/R
what are the two type of resistors
fixed
variable
this type of resistor is available with a large selector of resistance value that are set during manufacturing
fixed resistor
this type of resistor are designed so that their resistance can be changed
variable resistors
resistors color code number for (black)
0
resistors color code number for (brown)
1
resistors color code number for (red)
2
resistors color code number for (orange)
3
resistors color code number for (yellow)
4
resistors color code number for (green)
5
resistors color code number for (blue)
6
resistors color code number for (violet)
7
resistors color code number for (grey)
8
resistors color code number for (white)
9
