Card Set Information

2011-01-22 04:31:54

EL Score
Show Answers:

  1. formula for finding electrical power which relates Watts(P), Volts(V) and Amperes(I)
  2. current is measured in?
    amps with a ammeter
  3. Law of electric power
    calculates the amount of power consumed by an electric or electronic device
  4. ohm's law
    the relationship between electric pressure, current strength, and resistance in any circuit.
  5. electrical power is?
    the amount of energy consumed by an electric device. It is measured with an electric meter in WATTS
  6. electric current is?
    the flow of electric charge through a conducting material. it is measured with an Ammeter in Ampere
  7. 1 Ampere is equal to
    the flow of 1 coulomb of electricity past a given point per second
  8. Voltage is?
    the force that affects the rate at which electricity flows through a conductor. it is measured with a Voltmeter in Volts

    is the unit used to mesure elctrical pressure
  9. Resistance is?
    the opposition of a material to the flow of electricity through it. Measured with an Ohmmeter in OHMs.
  10. 1 Ohm = 1 Volt per AMP
  11. frequency is?
    the number of times that alternating current (AC) changes direction per second. Measured in Hertz(HZ)
  12. A battery
    stores electric charge and can furnish an electric current
  13. a Capacitor
    stores electric charge temporarily
  14. ground
    an extremely large reservoir of electrons that can supply or accept electrons as needed
  15. Rectifier
    changes alternating current(AC) to direct current(DC)
  16. Resistor
    supplies a resistance to a circuit
  17. Transformer
    can increase (step up) or decrease (step down) the voltage in a circuit
  18. Transistor
    controls the flow of electric current without the use of a vacuum (is a device that amplifies an electronic signal)
  19. a wire that is covered in black insulation is?
    the hot or live wire. if more than one hot wire is used then red and blue can be used
  20. Neutral wire is covered with what colored insulator?
    white or gray
  21. the grounding wire uses what color insulator?
    it is left bare, wrapped in paper or in green insulator
  22. Conductivity refers to?
    the ability of a given material to carry an electric charge
  23. a Rheostat does what?
    it changes the resistance in a circuit
  24. alternating current supplied to homes ordinarily has a frequency of how many Hertz(HZ)?
    60 hertz
  25. in most homes the items that used electricity are connected in?
    parallel circuits
  26. parellel circuits work how?
    has two or more separate branches for the current to flow. with this kin of circuit, if one electrical item fails, the current has alternate paths to follow and its flow to other items is not interrupted.
  27. series circuit works how?
    it only has a single branch for the current to flow. so if it fails the flow of current to all other items is blocked.
  28. contain solid-state semiconductor diodes that conduct electricity in only one direction
  29. the flow of electric charge in a a conductor between two point having a difference in potential is called?
  30. one HZ equals what?
    one complete cylce (or two complet alternationsof direction) per second.
  31. ampere is a measure of the ?
    strength of an electrical current
  32. Watts is calculated by?
    multiplying Vots times Amperes
  33. storage batteries are used on?
    cars, trucks and other vehicles. the negative post is thinner that the positive
  34. Capacity is a measure of how much current a wire can?
  35. short circuit is when?
    an exposed wire carrying current touches anotehr wire or ground metal. the current flos through the point of contact, creating a side circuit and bypassong its intended path.
  36. circuit overload
    when things draw more amperes than a circuit is designed to handle.
  37. circuit overload and short circuit will?
    trip the circut breaker, instantly stopping the flow of current
  38. Parallel Circuit
    has different parts on separate branches. One branch can be switched off without affecting the flow of current to other branches
  39. a charge of X coulombs moves through a circuit in X seconds. the current in the circuit can be found by?
    dividing the number of coulombs by the amount of time

    • Coulombs = Amperes
    • seconds
  40. three elements of a transistor are?
    collector , base, emitter
  41. Insulators are materials that?
    do not allow electrons to flow freely, thus preventing the formation of electric current. (rubber, wood, plastic and air)
  42. the watt is a measure of electrical
  43. the hertz is a measure of elctrical
  44. electron current is defined
    as the direct flow of electrons
  45. electric current flows from
    negatice to positive potential
  46. resistance is said to vary directly with the
    length of the wire. (the longer a wire the more resistance it has)
  47. black =0
    Brown =1
    red =2
  48. yellow =4
    green =5
    blue =6
    violet =7
    gray =8
    white =9
  49. the fourth stripe represents
    the resistor tolerance
  50. fourth silver is equal to?

    Gold is equal to?

    missing fourth stripe means its equal to?
    + or - 10 %

    + or - 5 %

    + or - 20%
  51. Nickel is a good _________ material?
    Magnetic ( not aluminum, tin, copper)
  52. any voltage of 600 volts or fewer is considered
    low potential
  53. the flow of AC is impeded not only by a circuits resistance bu also by its
  54. visible light occurs at what frequencies?
    1,000,000,000 MHz
  55. direct and continuous current flows always in the same
  56. the total resistance in a parallel circuit is alway less than the ___________
    smallest resistance
  57. A fuse must be place in _______ with the consuming device
  58. What are the effects of current?
    heating, magnetic, chemichal, and physiological
  59. Which of the following is a term applied to machines that convert either electrical energy into mechanical energy or mechanical energy into electrical energy by utilizing the principles of electromagnetic induction?
  60. Farads are units of resistance generally associated with
  61. The relation between currents from different branches arriving at a node in a circuit is given by
    Kirchoff's Law
  62. According to________ Law of current, in a closed network made up of various nodes and branches, the sum of all the currents entering the node is always equal to the sum of all the currents leaving the node.

    According to ________ Law, in the above node, I1 + I3 = I2 + I4. So, choice B is correct.
    Kirchoff's LAw
  63. When AC passes through a diode
    it rectifies the current
  64. If two capacitors are connected in parallel in a circuit, the total capacitance of the circuit is equal to the
    sum of the capacitance of the capacitors.
  65. What happens to the resistance and current in a conductor if the length of the conductor is increased without changing the cross-sectional area and the voltage?
    • Its resistance increases, but the current decreases.
    • (Therefore, when the conductor length is increased, its resistance increases)
  66. In which configuration of the amplifier will you get the highest power gain?
    A common emitter configuration amplifier acts both as a voltage and a current amplifier. In which configuration of the amplifier will you get the highest power gain?
  67. the propert of a circuit that opposes any change in voltage is
  68. another term for "cycles per second" is
  69. the process of trasmitting voice by varying the height of a carrier wave is known as
    amplitude modulation