Lesson 2 Flashcards
Rip open the proletariat
The ? in an electrical circuit is the electromotive force of the circuit.
Voltage
For current to be present in electrical circuits, the circuit has to be ? .
a. complete
b. connected to Earth
c. single-phase
d. 3-phase
a.complete
In a 60-cycle AC circuit, the voltage and current change amplitude and direction ? times per second.
120
In its simplest form, a capacitor is two conductors separated by insulation.
True or False
True
Kaufmann discovered that keeping the conductors of an AC circuit in close proximity to each other will keep the ? of the circuit low. Select one: a. current b. impedance c. voltage d. wattage
b.impedance
Current in an AC circuit will take which of the following paths while attempting to return to the source?
All conductive paths
Equipment such as switchboards and panelboards installed in an electrical system must have adequate ? ratings to ensure that extensive damage to equipment will not result from a ground-fault or short-circuit condition.
a. environmental
b. overload
c. short-circuit current
d. wattage
C.Short-circuit current
Fuses and circuit breakers are required to be marked with all but which of the following ratings?
Select one:
a. Ampere interrupting current rating (AIC)
b. Normal current rating
c. Resistance
d. Voltage
C.resistance
The highest current at rated voltage that a device is identified to interrupt under standard test conditions best defines which of the following? Select one: a. Interrupting rating b. Maximum impedance c. Maximum resistance d. Maximum voltage
a. Interrupting rating
The ? of an electrical system is the maximum current a system is capable of delivering at any point on the wiring installation. Select one: a. available fault current b. available number of phases c. available resistance d. available voltage
a. available fault current
An unintentional conducting connection between two ungrounded conductors of a circuit best describes which of the following?
a. Available fault current
b. Circuit withstand rating
c. Ground fault
d. Short circuit
D.short circuit
The amount of available fault current in an AC circuit is reduced by the overall ? of the circuit.
a. fuses
b. impedance
c. wattage
d. wire type
impedance
A(n) ? is defined as an unintentional, electrically conducting connection between an ungrounded conductor of an electrical circuit and the normally non–current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment, or earth. Select one: a. available fault current b. conductor withstand rating c. ground fault d. short circuit
C.ground fault
Inverse time operation of overcurrent devices means that the ? the current, the ? the device will react to the ground fault or short circuit event.
Select one:
a. faster / faster
b. higher / faster
c. higher / slower
d. lower / faster
B.higher/faster
Failure of conductor insulation is not a cause of failures in high-voltage and low-voltage electrical wiring.
Select one:
True
False
False
Which of the following are common causes of conductor insulation failure?
Select one:
a. Excessive voltage stress
b. Heat
c. Physical damage occurring during or after installation
d. All of the above
D.all of the above
Which of the following organizations developed the formulas to determine insulated and bare conductor current withstand ratings?
Select one:
a. General Cable Company
b. Insulated Cable Engineers Association (ICEA)
c. International Association of Electrical Inspectors (IAEI)
d. International Code Council (ICC)
b. Insulated Cable Engineers Association (ICEA)
Wire-type equipment grounding conductors must be capable of safely carrying high levels of available fault current for the duration of time it takes the overcurrent device for the circuit to open and clear the event.
True or False
True
Which of the following test instruments is commonly used to determine the integrity of conductor insulation? Select one: a. Amprobe b. Megohmmeter c. Thumper d. Wiggy
Megohmmeter
Wire-type equipment grounding conductors expressed in Table 250.122 of the NEC are approximately ? of the circuit conductor size. a. 20% b. 25% C. 50% d. 100%
b.25%
A(n) ? is defined as an electrically conductive path from the point of a ground fault on a wiring system through normally non–current-carrying conductors, equipment, or the Earth to the electrical supply source. Select one: a. effective ground-fault current path b. ground fault c. ground-fault current path d. short circuit
C,ground-fault current path
The highest current at rated voltage that a device is identified to interrupt under standard test conditions best defines which of the following? Select one: a. Current rating b. Interrupting rating c. Short-circuit current rating d. Voltage rating
b. Interrupting rating
