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Electrical Design Lightning and Static Electricity


Quiz Questions

1.The planet earth is similar to a huge battery continuously losing electrons to the atmosphere. These electrons could be lost in less than an hour unless the supply is continually replenished. It is widely agreed among physicists and scientists that thunderstorms occurring thousands of times daily around the earth return electrons to earth to maintain normal magnitude of electrons at or near the surface of the earth.
True
False
2. The purpose of air terminals is to intercept lightning discharge above facilities. Fig. 2-2.
True
False
3.Protection for oil storage tanks will depend on their inherent contact with earth. Where steel storage tanks are constructed on foundations of concrete or masonry, grounding will be provided in accordance with grounding schedule shown in table 2-1, regardless of tank height.
True
False
4. For an oil storage tank with a circumference of 452 feet what is the minimum number of ground connections.
2
3
5
5.The object of static electricity protection is to provide a means whereby static electricity charges, separated by whatever cause, may recombine harmlessly before sparking charges are attained.
True
False
6.In order for a static electricity charge to become a source of trouble. The following conditions must be considered:

  • There must be a means of static generation.
  • There must be a means of accumulation of a static charge capable of producing ignition.
  • There must be a means of spark discharge of the accumulated charge.
  • There must be an ignitable mixture or atmosphere at location of spark discharge to constitute an explosive or fire hazard.
  • The static potential must be maintained to constitute a hazard to personnel.

The static charge must be continuously conducted to constitute a compromise of classified communications.

True
False