EX. Module 1&2

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EX. Module 1&2
2012-02-11 18:52:19

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  1. An atom is the smallest possible particle
    that retains the characteristic of which of
    the following substances?
    A compound
  2. If light energy collides with an orbiting
    electron, what happens to the electron?
    The electron will jump to an orbit further from the nucleus
  3. When an atom gains or loses an electron,
    which of the following terms applies?
  4. What is the main difference between
    conductors, semiconductors, andinsulators?
    The number of free electrons
  5. Which of following actions describes the
    easiest way to accumulate a static electric
    Friction between two insulators
  6. Ferromagnetic materials have which of the
    following qualities?
    They are relatively easy to magnetize
  7. A material with low reluctance and high
    permeability such as iron or soft steel is
    used to make what type of magnet?
  8. Weber,s theory of magnetism assumes that
    magnetic material is composed of
    tiny molecular magnets
  9. According to the domain theory, if an atom
    with 26 electrons has 20 electrons spinning
    counterclock-wise, the atom is considered
    to be
  10. When directed drift takes place, at what
    speed does the effect take place?
    186,000 miles per second
  11. Carbon resistors have which of the
    following disadvantages?
    The resistance value changes with age
  12. What is the total number of connections on
    (a) a rheostat and (b) a potentiometer?
    (a) Two (b) three
  13. The property of inductance offers
    opposition to which of the following
    Changes in current
  14. What is the symbol for inductance?
  15. What is the unit of measurement for
  16. What physical property is similar to
  17. According to Lenz's Law, the induced
    emf produced by a change in current in
    an inductive circuit tends to have what
    effect on the current?
    It opposes either a rise or a fall in Current
  18. The direction of the induced voltage in 3. soft iron an inductor may be found by application
    of which of the following rules?
    The left-hand rule for generators
  19. How are inductors classified?
    By core type
  20. Which of the following factors will
    NOT affect the value of inductance of a
    Conductor tensility
  21. Why do large diameter coils have
    greater inductance than smaller diameter
    coils, all other factors being the same?
    Large diameter coils have more wire and thus more flux
  22. A soft iron core will increase inductance
    because it has which of the following
    Low permeability and high Reluctance
  23. An increase in the permeability of the
    core of a coil will increase which of the
    following coil characteristics?
    Magnetic flux
  24. If a coil is wound in layers, its
    inductance will be greater than that of a
    similar single-layer coil because of a
    flux linkage
  25. Regardless of the method used,
    inductance of a coil can ONLY be
    increased by increasing what coil
    Flux linkage
  26. What is the symbol used to denote the
    basic unit of measurement for
  27. Inductors experience copper loss for
    what reason?
    Because all inductors have resistance which dissipates power
  28. What term applies to the power loss in
    an iron core inductor due to the current
    induced in the core?
    Eddy-current loss
  29. Power consumed by an iron core
    inductor in reversing the magnetic field
    of the core is termed as what type of
    Hysteresis loss
  30. Capacitance and inductance in a circuit
    are similar in which of the following
    Both cause the storage of energy
  31. Capacitance is defined as the property of
    a circuit that
    opposes a change in voltage
  32. Electrostatic lines of force radiate from
    a charged particle along what type of
    Straight lines
  33. Which of the following characteristics
    of a capacitor can be varied WITHOUT
    altering its capacitance?
    Thickness of the dielectric
  34. The maximum voltage that can be
    applied to a capacitor without causing
    current flow through the dielectric is
    working voltage
  35. Which, if any, of the following
    conditions may cause a capacitor to
    suffer power losses?
    Dielectric hysteresis
  36. Rapid reversals in the polarity of the line
    voltage applied to a capacitor will cause
    what type of capacitor power loss?
  37. Has an oxide film Dielectric
  38. Can be adjusted by a
    screw setting
  39. A polarized capacitor
  40. Has a waxed paper dielectric
  41. An adjustable capacitor with a mica dielectric
  42. Which of the following defines transformer action?
    The transfer of energy from one circuit to another through electromagnetic action
  43. Which of the following is NOT a necessary element in a basic transformer?
    A magnetic shield
  44. The two types of transformer cores most
    commonly used are the shell-core and
  45. What is the principal difference between
    a high-voltage transformer and a lowvoltage
    A high-voltage transformer has more insulation between the layers of windings than does a low-voltage transformer
  46. What term applies to the current in the
    primary of a transformer that creates the
    magnetic field?
    Exciting current
  47. In the primary of a transformer, what
    opposes the current from the source?
    The self-induced emf
  48. Power lost in realigning domains
    Hysteresis loss
  49. Power dissipated by the resistance of the windings
    Copper loss
  50. Power loss caused by random core currents
    Eddy-current loss
  51. Used above 20 kHz
  52. The secondary is a tapped primary
  53. Used to deliver voltage from a source to a load
  54. Can be used to match impedance in a sound system