T115   10 0215   

JB10-38 Homework
35 points

OEET115

Back to Main Page
 
  • Read p. 42 to 46
  • Study diagram on p. 66
  • Read p. 76 ("How snap switches work . . .") to p. 84
  • Read p. 98 to p. 107  (stop at "Reducing Voltage Drop") 
  1. For a single-phase, 60 Hz motor, how many pushes does the rotor receive each second? ________________
  2. For a three-phase, 60 Hz motor, how many pushes does the rotor receive each second? ________________
  3. Can a three-phase motor be run with only three wires going to it? Yes or No.
  4. Is two-phase current widely used? Yes or No.
  5. Residential wiring uses three wires, red, black, and white. Is this single phase, two phase, or three phase wiring? ______________
  6. For single-phase AC, what is the formula for volt-amperes? _______________
  7. For three-phase AC, what is the formula for volt-amperes? ________________
  8. If the volt-amperes is equal to the watts, what is the power factor? _______________
  9. What is the formula for power factor? ____________
  10. What is the formula for AC watts (taking power factor into account)? _____________
  11. What two methods are used to correct for low power factor at an installation? _______________
  12. Looking at the diagram on page 66, is a ground bonding screw used at the feeder panel? Yes or No.
  13. What type of wiring is used for ordinary wiring of lamps in a building, series or parallel? _____________
  14. If you needed to have four switches controlling one lamp, 
    • How many single-pole switches would you need? 0, 1, 2, 3, or 4
    • How many three-way switches would you need?  0, 1, 2, 3, or 4
    • How many four-way switches would you need?   0, 1, 2, 3, or 4
  15. Which type of insulation is moisture resistant, THHN or THWN? ____________
  16. Which can carry more current, 14 AWG wire or 12 AWG wire? _____________
  17. 6 AWG wire has four times the cross-sectional area of 12 AWG wire. Can 6 AWG wire carry four times the current of 12 AWG wire? Yes or No.
  18. For wire running through an attic in Phoenix, would the temperature correction factor result in a thicker or a thinner wire than would be used in a cooler area? __________


 
Back to Main Page