12. Which of the following statements about ground faults is true? A. They can happen if a conductive tool is dropped in an energized equipment's electrical enclosure. B. They usually occur between any grounded circuit conductor and the equipment grounding conductor. C. They can't result from human error. D. They're often normal and typically intentional.

13. _______ current attempts to return to the source over any available conductive path.A. DirectB. AlternatingC. Ground-faultD. Arc-fault

Describe the operation of a circuit breaker in protecting a power system from faults.

X.a- The figure shows a fault condition in an ungrounded electrical system. Which of the following will occurbecause of the fault in this system?A. Only the overcurrent protector at Point A will trip open.B. The ground fault will heavily damage the service.C. Nothing will happen until a second ground fault occurs.D. The overcurrent protection will trip, shutting off all the line side power.

15. Which of the following conductors in a typical separable connection plug and receptacle has a firstmake, last-break feature?A. The neutral grounded conductorB. The equipment grounding conductorC. A center wye conductorD. The grounded delta conductor

A? Conductor is defined in NEC 240.2 as a conductor, other than a service conductor, having overcurrent protection ahead of its point of supply that exceeds the value permitted for similar conductors that are not taps. A. Faulted b. Tap c. Magnetic d. Copper-like

Why are circuit breakers and fuses ineffective in protecting against transient over voltage due to lighting and switching surges?

6.a. The amount of short-circuit current that flows depends upon the amperes available at the source ofpower, the length of the circuit, and what other primary factor?A. The presence of a ground fault currentB. Proper installation of the branch circuitC. Presence of no previous damage to the electrical systemD. The size of the conductors and voltage at which they operate6.b. You're evaluating the components of a multioccupancy building that won't have an on-site employee. Tobe compliant with the NEC, each occupant will need to have access to their ownA. service-disconnecting means.B. service conductor.C. cable attachment point.D. emergency fire water-pump disconnect.

On a 120/240 V, single-phase, three-wire system, identify the following: a. Voltage between one grounded conductor and one ungrounded conductor b. Voltage between two ungrounded conductors.