Principles Of Electricty Flashcards
Electricity def
Form of energy that products light, heat, and magnetic and chemical changes
Electrons def
A flow of tiny, negatively charged particles
Electric current def
Flow of electrons that move along a path called a conductor
Conductors def
Material that best transports electricity
Best are silver and copper; others include metals, graphite, carbon, and water-containing ions
Insulators def with examples
Material that doesn’t allow current to pass through; conductor is contained in an insulator
Silk, plastic, rubber, wood, glass, paper, air, brick, cloth, liquid paraffin, and pure distilled water
AMP/ampere def
A unit of electric strength; the amp rating indicates the number of electrons flowing on a line
1 ampere = _______ milliamperes
1000
Volt/voltage def
A unit of electric pressure; measures how hard the electrons are being forced or pushed by the source
OHM def
A unit of electric resistance; every conductor has a specific rate at which it will allow electrons to move through it; tells how difficult to push electrons though
The amount of resistance in a conductor is determined by
Size, material, and temperature
Watt def
A measure of how much electrical energy or power is being used per second
1 watt is a ___ amount of energy
Small
1 kilowatt =______ watts
1000
Source of how electric current is produced
Provides the force to move electrons in the conducting material
2 common sources of electric current
Battery
Generator
Battery description
Has a positive and a negative terminal; produces only direct current
Generator description
Most often used in a salon/spa; produces alternating current; uses mechanical energy to produce a flow of electrons
Two conditions that must exist for electric current to be produced
A source and a circuit
Circuit def
Closed path through which the electrons travel
Two types of circuits
Closed and open
Closed circuit def
Path of electron flow from source to operate appliance
Open circuit def
Path through which the electrons travel is broken
Two ways circuits can be connected to power loads
Parallel wiring
Series wiring
Parallel wiring def
More than one item can be plugged into the same circuit; each item can be run alone or at the same time
Series wiring def
All loads run at the same time; circuit travels from one load to the next
2 forms of electric current
Direct current (DC)
Alternating current (AC)
Direct current description
Electrons move at an even rate only in one direction (ex: battery)
Used in electrotherapy devices (galvanic)
Alternating current description
Most common current used in businesses and homes; electrons flow first in one direction and then in the other
Used in a high frequency device (tesla)
The nameplate of an appliance tells you
Frequency (Hz) needed
Volts needed (120v or 240v)
Watts appliance consumes per second (100w, 200w, etc)
What does an inverter do and an example
Changes direct current to alternating current
Mobile charger in car
What does a rectifier do and what is an example
Changes alternating current to direct current
Block between your wall plug in and device
What does a rheostat do and an example
Adjusts flow of current that can change volume or intensity of voltage
Dims lights; controls speed of motors
What does a transformer do and an example
Transfers electricity by an oscillating magnetic field that connects two or more electrical circuits
Reduces high voltage electricity to lower voltage
What does a capacitor do and an example
Stores an electrical charge
Unlike a battery, it releases energy quickly; does not produce new electrons
Lasers
Polarity refers to
The negative and positive poles at the ends of a circuit
Changes in polarity create
Waveforms
Waveform def
Visual representation of the output current that varies in time, strength, and direction
Waveform pulse is a combination of
Phases that make up a single portion of the waveform
Rectangular waveform description
Pulse wave
Has constant amplitude over the pulse duration
Square waveform description
Periodic waveform that instantly transitions between 2 levels of rise and fall times at a steady frequency
Sinusoidal waveform description
Smooth wave
Linear wave motion with periodic rise and fall times in a motion that is up-and-down or side-to-side
Saw-toothed waveform description
Periodic linear fave form in which the rise time and fall times at are different
Triangular waveform description
Periodic linear waveform that has rise and fall times that are equal
Overload circuit def
More current flows than the line is designed to carry
Fires can occur when an extension cord is used to attach four or five appliances to one wall outlet
Short circuit def
Can occur anytime a foreign conductor comes in contact with a wire carrying current to an appliance
Dropping an appliance into water will cause the current to flow though the water causing a short circuit
Safety measures of fuses
Cannot be reused
Contains a fine metal wire; allows current to flow through it
If overload occurs, fuse heats up and wire melts, breaking the circuit and cutting flow of electricity
2-prong grounding description
Polarized outlets feature 2 slots of different sizes
Slot for neutral wire is wider making it difficult to insert plug the wrong way
3-prong grounding description
In addition to vertical slots, round hole for the grounding conductor
Static electricity def
A stationary electric charge, typically produced by friction that causes sparks or crackling or the attraction of dust or hair; can be extremely dangerous
Fire extinguisher PASS
Pull pin
Aim hose
Squeeze handle
Spray chemical
