Midterms Flashcards
The form of energy generated by friction, induction, or chemical change has a magnetic, chemical, and radiant effect.
Electricity
He recorded that after rubbing amber with a piece of wool or fur other light objects such as straw or feathers were attracted to the amber.
Thales of Miletus
Latin and Greek term of electricity.
electricus - produce form amber by friction
elektor - beaming sun
Father of Electricity
William Gilbert
Built the first electric generator. Constructed of a ball of sulfur, rotated by a crank with one hand and rubbed with the other.
Otto von Guericke
Distinguished between materials that are conductors and nonconductors. Credited with discovering that electricity can flow.
Stephen Gray
Inventors of Leyden Jar; demonstrated that electricity can be stored for future use.
Ewald Georg von Kleist, Pieter van Musschenbroek
Suggested the existence of an electric fluid and surmised that an electric charge was made up of two types of electric forces; attractive and repulsive.
Benjamin Franklin
The famous kite experiment
Benjamin Franklin
Observed that a discharge of static electricity made a dead frog’s leg twitch; frog’s legs contained electricity and were released when it touched metal.
Luigi Galvani
Expanded Galvani’s findings and built voltaic pile, early type of electric cell/battery.
Alessandro Volta
Discovered that a magnetic field surrounds a current-carrying wire; electrical currents affected the needle on a compass.
Hans Christian Oersted
Observed that a coil of wires acts like a magnet when electrical current is pass through it.
Andre Marie Ampere
Demonstrated an electromagnetic device that was capable of lifting over a thousand pounds.
Dominique Francois Arago & Joseph Henry
Formulated law showing the relationship between volts, amps, and resistance.
Georg Simon Ohm
They developed mathematical relationships and rules concerning electrical circuiting.
James Prescott Joule, Gustav Robert Kirchhoff, James Clerk Maxwell
Conceived the idea of sending code messages over wires using the electromagnetic telegraph and a code of electrical impulses identified as dots and dashes.
Samuel Morse, Morse Code
Developed a crude electric motor.
Michael Faraday
First person to measure the amount of electricity and magnetism generated in a circuit.
Charles-Agustin de Coulomb
Developed a practical incandescent lamp.
Thomas Edison, Joseph Swan
First to patent the commercially feasible incandescent lamp. His Electric Light Company…
Thomas Edison, General Electric
Developed plans for an alternating current induction motor– successful utilization fo alternating current.
Nikola Tesla
Announced the first transformer.
Lucien Gaulard, John Dixon Gibbs
Bought the patent rights to Tesla’s alternating current system.
George Westinghouse
Date: The first alternating current power station was placed in operation; the output was limited to lighting.
1886
Date: Large-scale electric power distribution began when water flowing over Niagara Falls was diverted through a pair of high speed turbines which powered nearby manufacturing.
August 25, 1895
Date: Alternating current motor was introduced and commonly used electric motor in buildings.
1888
Negatively charged particle of an atom.
Electron
Positively charged particle of an atom. Weighs about 1850 times as much as electron.
Proton
Particle of an atom which is not electrically charged and weighs slightly more than proton.
Neutron
The five theory of Electricity
- all matters are made up of molecules.
- molecules are made up of atoms,
- atom contains n, e, p.
- n. is neutral; neither +/-
- electron of an aton of any substance could be transformed into another atom.
Rate or measure of power used or consumed.
Watt
Refers to the wire installation that supply current to light and convenient outlets.
Curcuit
Carries electric current without providing too much resistance to current flow.
Conductor
Materials that resist the flow of electricity.
Insulators
Materials that are neither good conductors nor good insulators.
Semiconductors
Electrons which are loosely bound to their nuclei.
Free electrons
When an atom has anequal number of electrons and protons, charges cancel…
Electrically neutral or uncharged
Electrically charged atom:
Electrons < Protons = ?
Elecrons > Protons = ?
Positively Charged
Negatively Charged
Term applied to an aton/molecule which is not electrically balanced.
Positively charged atom…
Negatively charged atom…
Ion
Positive Ion
Negative Ion
Logic behind attraction and repulsion
Attraction: Unlike charges attract
Repulsion: Like charges repel
When in balanced orbit, electrons move in spherical paths called…
Orbital shells
The outermost orbital shell of an atom
Valence shell
Capacity (number of electrons) per orbital shell
First: 2
Second: 8
Third: 18
Fourth: 32
In this theory, electric current is electron flow.
Classical Theory: Flow of Electrons
In this theory, electricity is tied to even smaller subatomic particles that possess either a positive or negative electromagnetic charge.
Modern Theory: Flow of Charged Particles
Electricity from friction
Static electricity
Electricity from heat
Thermoelectricity
Electricity from pressure
Piezoelectricity
Electricity from a chemical reaction.
Electrochemistry
Electricity from light.
Photo electricity
Electricity from magnetism
Magnetoelectricity
Current flow in one direction in an electrical circuit.
Direct Current (DC)
Continuous reversal of the direction of current flow.
Alternation Current (AC)
Standard unit used in measuring the strenth of an electric current.
Amperage/Inductive Flow
The driving force behind current flow.
Voltage/Electromotive Force
Friction or opposition to the flow of current by the wired and transformers.
Terms used in DC and AC…
Resistance
DC: Friction
AC: Impedance
Factors that influences conductor resistance
Composition of the Conductor
Length of Wire - the longer, higher resistance
Cross Sectional Area of Wire - bigger, lower resistance
Temperature
What is Ohm’s Law according to George Simon Ohm?
The higher the voltage, the higher the current, and the higher the resistance, the lower the current.
The rate at which the work is accomplished
Power
Define power factor
Measures how effectively the total delivered power is being used.
Amount of work accomplished
Energy
Flow or rate of electric force in a conductor
Electric Current
the standard unit used in measuring the strength of an electric current
Amperage
the driving force behind current flow
Voltage
friction or opposition to the flow of current by the wires and transformers
Resistance
continuous path along which an electric current can flow
electric circuit
a simple circuit is composed of the following
power source, load, set of conductors, control device
an uninterrupted path that allows continuous flow
closed circuit
current flow is interrupted; the switch is opened
open circuit
created if an inadvertent shortcut develops in a circuit; unintentional path
short circuit
current passes without branching off; seldom used
series circuit
if one load fails, the circuit remains closed; branching off
parallel circuit
circuit components are series and/or parallel in some parts
combination circuits
series circuit principles
shares the same amperage; total amperage is equal to the individual amperage
total voltage in a series circuit
summation of individual voltages
total resistance in a series circuit
summation of individual resistances
parallel circuit principles
shares the same voltage; total voltage is equal to the individual voltages
total amperage in a parallel circuit
summation of individual amperage
total resistance in a parallel circuit
less than any individual resistances (inverse)
