Here is the "Electricity  Basic Navy Training Courses" (NAVPERS 10622) in its
entirety. It should provide one of the Internet's best resources for people
seeking a basic electricity course  complete with examples worked out. See
copyright. See
Table of Contents.
ΒΆ U.S. GOVERNMENT PRINTING OFFICE; 1945  618779
CHAPTER 7 QUIZ ELECTRICAL POWER
1.
Does an empty lamp socket have force?
2. Is any work done by an open circuit?
3. Is any power
consumed by an open circuit?
4. A generator supplies a 72 ampere load at 600 volts. What is the power
consumed by the load in watts? In kilowatts? In hp?
5. A 50 hp motor draws 80 amperes at 600 volts.
What is the power input? Power output in watts? Efficiency?
6. The prime mover of a generator
furnishes 37 hp to the generator. The electrical load on the generator is 70 amperes at 440 volts. What is
the power input in watts? Power output in watts? Efficiency?
7. A power line has a drop of 18 volts
in transmitting a load of 75 amperes. How much power is lost in this line?
8. What is the resistance
of the line in problem 7?
9. If a line consumes 650 watts in transmitting 55 amperes, what is the potential
drop?
10. How much power will be consumed by a 75 hp motor operating at 80 percent efficiency? In
hp? In watts? In kilowatts?
Return to
Chapter 7
CHAPTER 7 ANSWERS ELECTRICAL POWER
1. Yes. There is an emf present. It tries to force current across the open circuit but cannot.
2. No, as long as no current flows it is a case of force but no motion.
3. No.
Again, force but no motion.
4.* 43,200 w. 43.2 kw. 57.9 hp.
5. 48,000 w. 37,300 w. 77.7 percent.
6. 27,602 w. 30,800
w. 89.6 percent.
7. 1,350 w.
8.
0.24 ohm.
9. 11.8 v.
10. 93.75 hp.
69,937.5 w. 69.94 w.
* The original manual gave
this as an incorrect answer: 16,128 w. 16,128 kw.
2.16 hp. Thanks to Lou Nickles for finding the error.
