9.2

  1. True/False

    In a direct current system the supply voltage must be generated at the level required by the load
    True
  2. The points of maximum attraction are called          
    Magnetic Poles
  3. There are three fundamental conditions that must exist before a voltage can be produced by magnetism.
    • One, there must be a conductor in which the
    • voltage can be produced.
    • Two, there must be a magnetic field in the
    • conductor's vicinity.
    • Three, there must be relative motion between the
    • field and the conductor.
  4. The direction of                is related to the direction of movement of the conductor through the magnetic field.
    current flow
  5. The electron movement is first in one direction, then in
    the other
    SINE WAVE
  6. True/False

    The voltage generated by the angular motion of a
    conductor through a magnetic field describes a sine wave
    True
  7. IN a Sine Wave, each 30° position describes not only the path of the conductor rotating in a two-pole field but the instantaneous values of               at each position
    voltage induced
  8. True/False

    The effective value of 1.414 peak AC amps is 1 amp DC, therefore the effective value of 1 peak AC amp is 0.707 amps DC
    True
  9. When the voltage or current rises from zero value to maximum and back to zero, it is called an                 
    alternation
  10. A sine wave describes 2 complete                in 360°. A cycle is defined as two               in a period of time.
    alternations, alternations
  11. Frequency is measured in cycles per second or HERTZ. Typically, the frequency of power systems in North America is             
    60 hertz
  12. What are some advantages of three-phase power
    over single-phase power
    • Generators operate more efficiently and have better regulation
    • generating three-phase power.
    • The transmission of power is cheaper due to the use of 25% less conductor material.
    • Three-phase motors are superior to single phase motors in cost and operating characteristics.
  13. Ohm's law that states that current is directly proportional to                       
    applied voltage
  14. True/False

    If AC voltage is applied to a resistance, the resultant current will be a sine wave
    True
  15. When two waves are precisely in step with one another they are said to be
    IN PHASE
  16. Waves do not go through their maximum and minimum points at the same instant of time, the waves are said to be
    OUT OF PHASE
  17. To further describe the phase relationship between two waves, the terms LEAD and LAG are used. The amount by which one wave leads or lags another is measured in              
    degrees
  18. True/False

    It is possible for one wave to lead or lag another by any number of degrees, except zero or 360
    True
  19. Total opposition to current flow in an AC circuit is called
    IMPEDANCE
  20. True/False

    It is the impedance of an AC circuit that may cause the voltage or current to be out phase with each other.
    True
  21. What are the oppositions to current in an AC circuit
    RESISTANCE, CAPACITIVE REACTANCE, and INDUCTIVE REACTANCE
  22. True/False

    In a DC circuit, the net opposition to current flow in a circuit is
    composed of only one electrical value -- RESISTANCE
    True
  23. The opposition to current flow that is produced merely by a
    conductor's inability to perfectly conduct current is resistance
    Resistance
  24. The transfer of energy through the electrostatic field surrounding the conductor is known as
    CAPACITANCE
  25. True/False

    The greater the "rate of change" in voltage, the greater the capacitance on the circuit
    True
  26. True/False

    In capacitive circuits, current leads voltage
    True
  27. True/False

    In an inductive circuit, the current leads the applied voltage
    False - lags
  28. The transfer of energy through the electromagnetic field surrounding the conductor is known as
    Inductive Reactance
  29. During the out-of-phase periods, the product of the Voltage and Amps produces a negative value. This portion of the circuit is known as                    .
    Reactive Power or VAR (Volt Amperes Reactive)
  30. True/False

    VAR is the portion of the circuit's energy that is
    used to support electromagnetic and/or electrostatic fields
    True
  31. The product of the applied voltage and the total
    circuit current ( I× E)
    Apparent Power
  32. The product of apparent power and power factor
    True power
  33. True/False

    True Power is the product of the applied voltage and the portion of the circuit current that are "in-phase" with the voltage.
    True
  34. The energy that reacts to changes in the circuit
    Reactive Power (VAR)
  35. VAR is the product of the applied voltage and the portion of the circuit's current that is                   with the voltage
    "out-of-phase"
  36. True/False

    The current flowing in one winding of a DELTA-connected transformer are less than the current flowing on the one phase of the line supplying the bank
    True
  37. True/False

    Bank ammeters read the phase current of the circuit.
    True
  38. One of the benefits of a DELTA system is that one phase of a three phase bank can be removed and operated                . The capacity of the bank is reduced to approximately              ; however, the three-phase system can continue to operate.
    OPEN DELTA, 58%
  39. True/False

    The current flowing in one phase of a WYE connected bank is the
    same as the current flowing in the line supplying the bank
    True
  40. The voltage across one winding of a WYE connected transformer is always                the line voltage of the supply circuit
    less than
  41. Generally the voltmeters on a power bank convert            voltage to              voltage. Therefore; Meter volts = line volts
    phase, line
  42. Any physical quantity that has both magnitude and direction, such as force or velocity, is called a                   .
    vector quantity
Author
Benjammincash
ID
355183
Card Set
9.2
Description
Electromagnetic Induction and Generation
Updated