Electricity 1

number of protons in an element

hydrogen --> helium

an element with a different # of neutrons

element with a negative or positive charge

the particular sphere that an electron is in

the more energy the electron shell is giving off

a substance through which current flows

a substance that prevents electrical currents from flowing

a substance in which current flows fairly well

a substance in which current does not flow as well as a conductor

pure silver, copper, aluminum, iron, steel

mercury, salt, water

Unit of electrical resistance

semiconductor in which most of the charge carriers are electrons

semiconductor in which most of the charge carriers are holes

the more abundant type of charge in a semiconductor

the less abundant type of charge in a semiconductor

unit of electrical charge, about 6 quintillion (18 zeroes) electrons

movement of charge carriers in a substance

unit of electrical current, 1 coulomb per second

potentially lethal electric current

buildup of electric charge on the surface of objects

the current that between positive polarity in one place and negative in another

unit of EMF/potential

110 - 130 volts

the type of radiant energy that a lightbulb gives off

an EMF of 1 volt, across a resistance of 1 ohm, will cause a current of 1 ampere to flow

the current is doubled

the current is cut in half

visible light is changed into electrical energy

potential difference between two points

lines representing the potential difference between two points

a few miliamperes gives off a shock

10-50 amperes of current in an entire household

resistance per unit area

measurement of resistivity

the ability of a substance to conduct electricity

unit of conductance

1/conductance

1/resistance

1 kilohme = millisiemens, in terms of resistance

decreases as length increases

unit of power

rate at which energy is expended in the form of heat

P = EI

I = P/E

E= P/I

.000000000001

.00000001

.000001

.001

1000

1000000

1000000000

1000000000000

power dissipated over time

unit of energy

1 watt of power dissipated for 1 hour of time

1 J = 1 watt-second

current goes in one direction

current goes in both directions

every 1/20 of a second

circuit that changes ac to dc

the voltage at a any point in time

maximum instantaneous voltage

objects that can easily become magnetized

unit of measurement of magnetic fields

unit of measurement of small magnetic fields

force that produce magnetic flux

measure of magnemotive force

amperes multiplied by the turns

magnetic field strengt

the amount of magnetic flux per square meter

1 Wb/m

.0001 T

when half of the ac wave is cut off, decreasing the signal

His kite experiment demonstrated that lightning is electricity. He was the first to use the terms positive and negative charge.

While working as an instrument maker at the University of Glasgow, Watt became interested in the technology of steam engines. He realised that contemporary engine designs wasted a great deal of energy by repeatedly cooling and re-heating the cylinder. Watt introduced a design enhancement, the separate condenser, which avoided this waste of energy and radically improved the power, efficiency, and cost-effectiveness of steam engines. He developed the concept of horsepower. The SI unit of energy, the watt was named after him.

Thomson did more than any other electrician up to his time in introducing accurate methods and apparatus for measuring electricity. As early as 1845 he pointed out that the experimental results of William Snow Harris were in accordance with the laws of Coulomb. In the Memoirs of the Roman Academy of Sciences for 1857 he published a description of his new divided ring electrometer, based on the old electroscope of Johann Gottlieb Friedrich von Bohnenberger and he introduced a chain or series of effective instruments, including the quadrant electrometer, which cover the entire field of electrostatic measurement. He invented the current balance, also known as the Kelvin balance or Ampere balance (SiC), for the precise specification of the ampere, the standard unit of electric current.

a German physicist was the discoverer of the "Seebeck effect".He twisted two wires made of different metals and heated a junction where the two wires met. He produced a small current. The current is the result of a flow of heat from the hot to the cold junction. This is called thermoelectricity. Thermo is a Greek word meaning heat.

an Englishman, made one of the most significant discoveries in the history of electricity: Electromagnetic induction. His pioneering work dealt with how electric currents work.

a Scottish mathematician translated Faraday's theories into mathematical expressions. Maxwell was one of the finest mathematicians in history. A maxwell is the electromagnetic unit of magnetic flux, named in his honor.

patented the first system of distributed electricity, invented the electric light bulb.

Tesla's patents and theoretical work formed the basis of modern alternating current (AC) electric power systems, including the polyphase system of electrical distribution and the AC motor, which helped usher in the Second Industrial Revolution.Tesla's system triumphed to make possible the first large-scale harnessing of Niagara Falls with the first hydroelectric plant in the United States in 1886.

was awarded the contract to build the first generators at Niagara Falls. He used his money to buy up patents in the electric field. One of the inventions he bought was the transformer from William Stanley. Westinghouse invented the air brake system to stop trains, the first of more than one hundred patents he would receive in this area alone. He soon founded the Westinghouse Air Brake Company in 1869.

A unit of sound level is called a bel in his honor. Sound levels are measured in tenths of a bel, or decibels. The abbreviation for decibel is dB.

a German physicist, laid the ground work for the vacuum tube. He laid the foundation for the future development of radio, telephone, telegraph, and even television. He was one of the first people to demonstrate the existence of electric waves.

a German chemist and physicist, made the vital discovery which led to the first nuclear reactor. He uncovered the process of nuclear fission by which nuclei of atoms of heavy elements can break into smaller nuclei, in the process releasing large quantities of energy. Hahn was awarded the Nobel prize for chemistry in 1944.

Einstein's formula proved that one gram of mass can be converted into a torrential amount of energy. To do this, the activity of the atoms has to occur in the nucleus. E = energy, M = mass, and C = the speed of light which is 186,000 miles per second. When you square 186,000 you can see it would only take a small amount of mass to produce a huge amount of energy.

when a temperature difference creates an electric potential or an electric potential creates a temperature difference.

the production of voltage across a conductor situated in a changing magnetic field or a conductor moving through a stationary magnetic field.