Electricity 1

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Electricity 1
2010-07-10 21:02:20

Electricity, Ch. 1-2
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  1. atomic number
    number of protons in an element
  2. fusion energy
    hydrogen --> helium
  3. isotope
    an element with a different # of neutrons
  4. ion
    element with a negative or positive charge
  5. electron shell
    the particular sphere that an electron is in
  6. further away the electron shell
    the more energy the electron shell is giving off
  7. conductor
    a substance through which current flows
  8. insulator
    a substance that prevents electrical currents from flowing
  9. resistor
    a substance in which current flows fairly well
  10. semiconductor
    a substance in which current does not flow as well as a conductor
  11. examples of good solid conductors
    pure silver, copper, aluminum, iron, steel
  12. examples of good liquid conductors
    mercury, salt, water
  13. Ohm
    Unit of electrical resistance
  14. N-Type
    semiconductor in which most of the charge carriers are electrons
  15. P-Type
    semiconductor in which most of the charge carriers are holes
  16. majority carrier
    the more abundant type of charge in a semiconductor
  17. minority carrier
    the less abundant type of charge in a semiconductor
  18. coulomb
    unit of electrical charge, about 6 quintillion (18 zeroes) electrons
  19. current (I)
    movement of charge carriers in a substance
  20. Ampere (A)
    unit of electrical current, 1 coulomb per second
  21. 100 mA
    potentially lethal electric current
  22. static electricity
    buildup of electric charge on the surface of objects
  23. EMF (electromotive force)
    the current that between positive polarity in one place and negative in another
  24. voltage (V)
    unit of EMF/potential
  25. voltage of ordinary household electronics
    110 - 130 volts
  26. infrared (IR)
    the type of radiant energy that a lightbulb gives off
  27. Ohm's Law
    an EMF of 1 volt, across a resistance of 1 ohm, will cause a current of 1 ampere to flow
  28. EMF is doubled
    the current is doubled
  29. resistance is doubled
    the current is cut in half
  30. photovoltaic cell
    visible light is changed into electrical energy
  31. electric field
    potential difference between two points
  32. electric lines of flux
    lines representing the potential difference between two points
  33. amount of current that gives off a shock
    a few miliamperes gives off a shock
  34. amount of current in an entire household
    10-50 amperes of current in an entire household
  35. resistivity
    resistance per unit area
  36. ohms/ft
    measurement of resistivity
  37. conductance
    the ability of a substance to conduct electricity
  38. Siemen (S)
    unit of conductance
  39. resistance, in terms of conductance
  40. conductance, in terms of resistance
  41. 1 mS
    1 kilohme = millisiemens, in terms of resistance
  42. conductance, in terms of wire length
    decreases as length increases
  43. Watts (W)
    unit of power
  44. power (P)
    rate at which energy is expended in the form of heat
  45. power, in terms of voltage and current
    P = EI
  46. current, in terms of power and voltage
    I = P/E
  47. voltage, in terms of power and current
    E= P/I
  48. pico- (p)
  49. nano- (n)
  50. micro- (u)
  51. milli- (m)
  52. kilo- (k)
  53. mega- (M)
  54. giga- (G)
  55. tera- (T)
  56. energy
    power dissipated over time
  57. Joule (J)
    unit of energy
  58. watt-hour
    1 watt of power dissipated for 1 hour of time
  59. energy, in terms of power and time
    1 J = 1 watt-second
  60. direct current (dc)
    current goes in one direction
  61. alternating current (ac)
    current goes in both directions
  62. most ac household items reverses at this rate
    every 1/20 of a second
  63. rectifier
    circuit that changes ac to dc
  64. instantaneous voltage
    the voltage at a any point in time
  65. effective voltage
    maximum instantaneous voltage
  66. ferromagnetic
    objects that can easily become magnetized
  67. Weber (Wb)
    unit of measurement of magnetic fields
  68. Maxwell (Mx)
    unit of measurement of small magnetic fields
  69. magnemotive force
    force that produce magnetic flux
  70. ampere turn (At)
    measure of magnemotive force
  71. ampere turns, in terms of curren
    amperes multiplied by the turns
  72. magnetic flux
    magnetic field strengt
  73. flux density
    the amount of magnetic flux per square meter
  74. Tesla (T)
    1 Wb/m
  75. Gause (G)
    .0001 T
  76. half wave rectificiation
    when half of the ac wave is cut off, decreasing the signal
  77. Benjamin Franklin (1706-1790)
    His kite experiment demonstrated that lightning is electricity. He was the first to use the terms positive and negative charge.
  78. James Watt (1736-1819)
    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.
  79. William Thomson, Lord Kelvin (1824-1907)
    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.
  80. Thomas Seebeck (1770-1831)
    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.
  81. Michael Faraday (1791-1867)
    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.
  82. James Maxwell (1831-1879)
    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.
  83. Thomas Edison (1847-1931)
    patented the first system of distributed electricity, invented the electric light bulb.
  84. Nikola Tesla
    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.
  85. George Westinghouse (1846-1914)
    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.
  86. Alexander Graham Bell (1847-1922)
    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.
  87. Heinrich Hertz (1857-1894)
    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.
  88. Otto Hahn (1879-1968),
    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.
  89. Albert Einstein (1879-1955)
    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.
  90. Thermoelectricity
    when a temperature difference creates an electric potential or an electric potential creates a temperature difference.
  91. Electromagnetic induction
    the production of voltage across a conductor situated in a changing magnetic field or a conductor moving through a stationary magnetic field.