Low Voltage & Power Limited Systems
Think you have a handle on low voltage and power limited systems? Test your knowledge of rules governing the installations and upgrades of these systems.
Questions and Answers
- 1.
Electrical metal tubing must be threaded when used in high-hazard locations.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Electrical metal tubing does not need to be threaded when used in high-hazard locations. In fact, in high-hazard locations, it is recommended to use rigid metal conduit (RMC) or intermediate metal conduit (IMC) instead of electrical metal tubing (EMT) as they provide better protection against physical damage and fire hazards. Therefore, the given statement is false.Rate this question:
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- 2.
EMT must be securely fastened within ____ feet of every box, cabinet or termination fitting, and at intervals not exceeding ____ feet.
- A.
5 / 10
- B.
3 / 5
- C.
1 / 5
- D.
3 / 10
Correct Answer
D. 3 / 10Explanation
EMT (Electrical Metallic Tubing) must be securely fastened within 3 feet of every box, cabinet, or termination fitting, and at intervals not exceeding 10 feet. This ensures that the EMT is properly supported and reduces the risk of damage or disconnection. By securely fastening the EMT at regular intervals, it helps maintain the integrity of the electrical installation and ensures the safety of the wiring system.Rate this question:
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- 3.
EMT may be used as the sole support for cameras mounted outside when boxes are attached
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
EMT (Electrical Metallic Tubing) is not suitable as the sole support for cameras mounted outside when boxes are attached. EMT is primarily used for protecting and routing electrical wires, and it may not provide enough stability or durability to support the weight of cameras and boxes in outdoor environments. Additional supports or mounting systems specifically designed for outdoor camera installations are typically required to ensure proper stability and security. Therefore, the correct answer is false.Rate this question:
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- 4.
EMT installed horizontally in holes bored or punched in wood or metal framing members, or in notches in wooden members, is not considered supported.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
When EMT (Electrical Metallic Tubing) is installed horizontally in holes bored or punched in wood or metal framing members, or in notches in wooden members, it is considered supported. This means that it is securely held in place and does not require additional support. Therefore, the correct answer is False.Rate this question:
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- 5.
The maximum distance between pull points is ____.
- A.
50 feet
- B.
100 feet
- C.
The length of the available snake
- D.
Not applicable. The code specifies no maximum distance
Correct Answer
D. Not applicable. The code specifies no maximum distanceExplanation
The correct answer is "not applicable. The code specifies no maximum distance". This means that there is no specific limit or maximum distance mentioned in the code for the pull points. The code does not impose any restrictions on the distance between the pull points, so the maximum distance is not applicable in this case.Rate this question:
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- 6.
To protect wire from abrasion, bushings are required by a fitting that provides a smooth, rounded insulating surface for all wires ____ AWG and smaller.
- A.
6
- B.
10
- C.
16
- D.
18
- E.
All wires of all sizes require such a bushing
Correct Answer
A. 6Explanation
To protect wires from abrasion, bushings are required for all wires 6 AWG and smaller. Bushings provide a smooth and rounded insulating surface, which helps prevent the wires from getting damaged due to friction or rubbing against other surfaces. The use of bushings is particularly important for smaller gauge wires as they are more susceptible to abrasion. Therefore, the correct answer is 6.Rate this question:
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- 7.
Boxes or other enclosures are required for Class 2 and Class 3 splices, or terminations.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Boxes or other enclosures are not required for Class 2 and Class 3 splices or terminations.Rate this question:
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- 8.
Under a roadway, buried nonmetallic raceways must be buried at least ____.
- A.
6 in.
- B.
18 in.
- C.
2 ft.
- D.
6 ft.
Correct Answer
C. 2 ft.Explanation
Nonmetallic raceways are typically used for underground electrical installations. These raceways must be buried at a sufficient depth to protect them from damage and ensure safety. A depth of 2 ft. is necessary to provide adequate protection against accidental excavation or damage from vehicles passing over the roadway. This depth also helps to prevent the raceways from being exposed to extreme temperatures or other environmental factors that could affect their performance.Rate this question:
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- 9.
Separation of ____ is required between Class 2 or Class 3 circuits and between raceways or cables containing power conductors.
- A.
1/4 in.
- B.
1/2 in.
- C.
2 in.
- D.
Not applicable. No separation is required.
Correct Answer
D. Not applicable. No separation is required.Explanation
No separation is required between Class 2 or Class 3 circuits and between raceways or cables containing power conductors.Rate this question:
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- 10.
Class 2 cables must not be supported by a raceway unless ____.
- A.
The raceway is rigid metal conduit
- B.
The raceway provides power to the equipment controlled by the Class 2 cable
- C.
Plenum wire ties are used at intervals of 18 inches or less
- D.
Not applicable. No exception exists
Correct Answer
B. The raceway provides power to the equipment controlled by the Class 2 cableExplanation
Class 2 cables must not be supported by a raceway unless the raceway provides power to the equipment controlled by the Class 2 cable. This means that if the raceway is not providing power to the equipment, it should not be used to support the Class 2 cable. This requirement ensures that the raceway is only used for supporting cables that are directly related to the equipment's power supply.Rate this question:
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- 11.
Optical fiber cables not terminated at equipment and not identified for future use with a tag ____.
- A.
Are considered abandoned and must be removed
- B.
Pose no hazard because they carry no current
- C.
Can be “toned out” at a future date for use
- D.
May be left in place only in industrial applications
Correct Answer
A. Are considered abandoned and must be removedExplanation
If optical fiber cables are not terminated at equipment and not identified for future use with a tag, they are considered abandoned and must be removed. This means that these cables are no longer in use or needed, and leaving them in place can cause clutter and confusion. Therefore, it is necessary to remove these abandoned cables to maintain a clean and organized environment.Rate this question:
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- 12.
Which of the following is not permitted?
- A.
Cables may be supported by the structural components of the building.
- B.
Raceways and cables may be supported by independent support wires attached to the suspended ceiling.
- C.
Cables may be attached to the support wire of a suspended ceiling.
- D.
Cables may be secured by straps, staples, hangers or similar fittings, as long as they are designed not to damage the cable.
Correct Answer
C. Cables may be attached to the support wire of a suspended ceiling.Explanation
The correct answer is "Cables may be attached to the support wire of a suspended ceiling." This is not permitted because according to electrical codes and regulations, cables should not be attached directly to the support wire of a suspended ceiling. Instead, raceways and cables should be supported by independent support wires attached to the suspended ceiling. Attaching cables directly to the support wire can pose a safety hazard and may not provide proper support for the cables.Rate this question:
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- 13.
Unless protected by a steel plate, cables cannot be closer than ____ from the edge of framing membersor furring strips.
- A.
1/2 in.
- B.
1 in.
- C.
1 1/4 in.
- D.
1 1/2 in.
Correct Answer
C. 1 1/4 in.Explanation
Cables need to be protected by a steel plate if they are closer than 1 1/4 inches from the edge of framing members or furring strips.Rate this question:
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- 14.
Working spaces for equipment operating at not more than 30VAC or 60VAC can be smaller than the distance specified in Table 110.26.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The statement is true because according to Table 110.26 in the National Electrical Code (NEC), the specified distances for working spaces around electrical equipment are based on the voltage level. For equipment operating at not more than 30VAC or 60VAC, the required working space can be smaller than what is specified in the table. This is because lower voltage levels pose less risk of electrical shock or arc flash hazards, so the NEC allows for smaller working spaces in these cases.Rate this question:
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Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.
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Current Version
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Oct 12, 2023Quiz Edited by
ProProfs Editorial Team -
Dec 12, 2014Quiz Created by
Vankirka
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