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Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

12. What NEC Article covers Community Antenna and Television and Radio Distribution? Select one: a. 820 b. 800 c. 760 d. 810

a

23. Smoke detectors ___ permitted to be supplied by lighting branch circuits. Select one: a. are b. are not

a

24. The NEC defines a Signaling Circuit in ___. Select one: a. Article 100 b. 725.1 c. 725.10(C) d. 800.3(B)(2)

a

9. ___ offer substantial resistance to the flow of electricity, and are therefore good insulators. Select one: a. Rubber and dry wood b. Rubber and treated wood c. Duct tape and dry wood d. Duct tape and treated wood

a

EMI is an abbreviation for ___. Select one: a. Electro- Magnetic Interference b. Energy Management Interface c. Environmental Measuring Instrument d. none of these

a

17. When VDV (voice or data or video) outlets are installed in a wall adjacent to a power receptacle, the VDV outlet should be installed ___ the power outlet. Select one: a. higher than b. at the same height as c. lower than

b

26. It ___ permitted to install Class 2 wiring in the same raceway or enclosure as electric light and power wiring. Select one: a. is b. is not

b

28. When a 120-volt receptacle and a TV outlet are mounted in a double-gang box, ___ is required in the box to isolate the TV conductors from the power wiring. Select one: a. lead shielding b. a barrier c. double grounding d. double insulation

b

A four-pair communication cable will contain ___ conductors. Select one: a. 4 b. 8 c. 12 d. 16 e. 20

b

A two-pair communication cable contains ___ conductors. Select one: a. 8 b. 4 c. 6 d. 2 e. 16

b

The human body has a ___ resistance to electricity, making it a good ___. Select one: a. low, insulator b. low, conductor c. high, insulator d. high, conductor

b

1. The term gigahertz means ___ per second. Select one: a. million cycles b. million bytes c. billion cycles d. billion bytes

c

14. According to NEC Article 725, the outputs of two different Class 2 transformers can be connected together___. Select one: a. if they have the same VA rating b. if they are power limited c. if they are listed for interconnection d. under no condition of use

c

2. RFI is an abbreviation for ___. Select one: a. Resonant Filter Interception b. Radial Fluorescent Impedance c. Radio Frequency Interference d. none of these

c

25. Article 725 in the NEC classifies transformers and low-voltage wiring for doorbells and chimes as ___circuits. Select one: a. power-limited b. Class 1 c. Class 2 d. Class 3

c

29. On the EWR plans, ___ smoke alarms (detectors) are shown on the first floor. Select one: a. 8 b. 4 c. 6 d. 10

c

31. On the EWR plans, the low-voltage transformer for the chime is located in the ___. Select one: a. kitchen b. entry c. workshop d. living room

c

32. On the EWR plans, the TV outlets in the recreation room should be mounted ___ of the box. Select one: a. 12" A.F.F. to the bottom b. 12" A.F.F. to the top c. 12" A.F.F. to the center d. 54" A.F.F. to the center

c

33. On the EWR plans, ___ pushbutton switch(es) is (are) shown on the east-facing walls. Select one: a. 1 b. 3 c. 0 d. 2

c

34. On the EWR plans, ___ pushbutton switch(es) is (are) shown on the interior walls. Select one: a. 1 b. 3 c. 0 d. 2

c

35. The EWR plans require that the smoke detectors ___. I. operate on 120-volts AC with battery backup II. cause all detectors in the house to sound should any one sound an alarm Select one: a. I only b. II only c. both I and II d. either I or II e. neither I nor II

c

8. The most common and serious electrical injuries occur when electrical ___ flows between the hands and feet. Select one: a. resistance b. voltage c. current d. shock

c

Which of these is the National Fire Alarm and Signaling Code? Select one: a. NFPA 70 b. Article 760 c. NFPA 72 d. none of these

c

10. Use heavy-duty grounded extension cords. Heavy-duty cords will have a marking on the insulation such as___. Select one: a. S b. SJ c. SJO d. any of these

d

11. The electrical resistance of wet skin is at least ___ times less than dry skin. Select one: a. 25 b. 50 c. 75 d. 100

d

13. When required to be grounded, the shield of a coax cable shall be grounded with at least a size ___ AWG conductor according to NEC Article 820. Select one: a. 6 b. 8 c. 10 d. 14

d

15. Although not a Code requirement, TV wiring should generally be kept at least two inches from power conductors that are in raceways or cables, should not pass through the same stud holes as power cables, and should cross power cables at right angles in order to reduce ___. Select one: a. heat b. congestion c. clutter d. interference

d

21. Generally, what size bell wire is used for chime systems in a residence? Select one: a. 12 b. 14 c. 16 d. 18 e. 20

d

22. An 18 watt chime system that draws 1.5 amps is to be installed in a commercial building. For this circuit, 330feet of 18 AWG solid copper cable is used. The voltage at the transformer secondary is 13.2 volts. What minimum size wire would be required to supply no less than 11.5 volts to the chime? Use K = 12.3. Select one: a. 12 b. 18 c. 14 d. 10 e. 16

d

30. On the EWR plans, ___ heat alarms (detectors) are shown in the basement. Select one: a. 2 b. 4 c. 3 d. 1

d

18. What is the minimum VA rating of a transformer used to supply power to two separate chimes that each have a rating of 11 watts? Both chimes will sound at the same time. Select one: a. 5 b. 10 c. 15 d. 20 e. 30

e

27. Television antenna and lead-in wires are covered under Article ___. Select one: a. 800 b. 250 c. 820 d. 810 e. 210

e


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