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2008 NEC Refresher Part 2 Practice Test 5

Course Name: 2008 NEC Review
Quiz Number:  No. 20
Teacher:  Gerald Newton
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No. of Questions= 20

1 What is the duty cycle for a spot welder supplied by a 60-Hz system (216,000 cycles per hour) making three hundred 15-cycle welds per hour?
a) 1percent
b) 2.1 percent
c) 3.2 percent
2 In general, where installed in raceways conductors larger than No. _____shall be stranded.
a) 10
b) 8
c) 6
d) 4
3 With a feeder load of 14 kW on a household electric range, the maximum unbalanced load shall be considered to carry a load of : (chose the closest answer)
a) 41 amperes
b) 26 amperes
c) 33 amperes
4 Where THHN conductors are added to an existing raceway that contains older 60 degree C insulated conductors, the ampacity of the THHN conductors cannot exceed _______.
a) The ampacities in the 60 degree column
b) The ampacities in the 75 degree column
c) The ampacities in the 90 degree column
d) The ampacities in the 90 degree column with 60 percent derating.
5 The ampacity of a 75 degree C. rated conductor in an ambient of 75 degrees C. is ____.
a) 0 amperes
b) 90 percent of its normal ampacity
c) 60 percent of its 75 degree ampacity
6 Wiring to receptacles under raised floors in computer rooms shall be ______.
a) Type MI cable, Type MC cable, or Type AC cable
b) In rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, electrical metallic tubing, metal wireway, surface metal raceway with metal cover, flexible metal conduit, liquidtight flexible metal or nonmetallic conduit
c) Nonmetallic Shielded Cable (NMB)
d) All of the above
e) A or B of the above
7 Intrinsically safe circuits can be identified using ______.
a) blue color
b) red color
c) orange color
d) any color
8 Nonincenditive circuits shall be permitted to be used in ______areas.
a) Class I, Division 2
b) Class I, Division 1
c) Class III
d) All of the above
e) Only a and c.
9 What is the maximum distance allowed for spacing supports for No. 10 copper conductors which are vertically installed in raceways.
a) 25 feet
b) 50 feet
c) 100 feet
d) 150 feet
10 Flat conductor cable installations:
a) Are suitable for school installations
b) Must be installed under carpet squares
c) Can only be installed on concrete floors
d) Are limited to voltages not exceeding 150 volts.
11 A restaurant may be wired using nonmetallic sheathed cable when: (1) The building is NOT required to be fire rated construction. (2) The building does not exceed 3 floors and the restaurant occupancy load is less than 100 persons. (Select the best answer.)
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 or 2
12 Mineral insulated cable is approved for almost all locations and conditions but one of the below. Which is it?`
a) Where embedded in concrete
b) Exposed to gasoline
c) where exposed to destructive corrosive conditions
13 Type AC cable shall be constructed to include:
a) At least 3 conductors
b) An insulated equipment grounding conductor
c) An internal bonding strip of copper or aluminum in intimate contact with the armor for its entire length.
14 The pull box below is used for conductors larger than No. 6. What are the required minimum dimensions for X and Y?
a) X = 24 inches, Y = 16 inches
b) X = 20 inches, Y = 24 inches
c) X = 24 inches, Y = 24 inches
d) X = 30 inches, Y = 30 inches
15 How many 1/2 inch diameter control cables can be installed in a 18 inch ladder type cable tray with 6 inch high sides?
a) 100
b) 125
c) 150
d) 275
16 If a service consists of 4 each 500 kcmil copper conductors per phase in a gutter and is 3 -phase 4 wire 480/277 volts what size copper bonding jumper is required on the supply side of the service disconnecting means?
a) 3/0
b) 250 kcmil
c) 300 kcmil
d) 350 kcmil
17 Disregarding exceptions the minimum cover requirement for a direct burial cable with a circuit voltage of 7200 volts to ground is _______.
a) 30 inches
b) 36 inches
c) 42 inches
d) 48 inches
18 When is ground fault protection required on a service?
a) 277/480 volts solidly grounded Wye rated at 1000 amperes or more
b) 120/208 volts Wye rated 1200 amperes or more
c) 120/240 volts rated 1000 amperes or more
d) All of the above
19 How many three way and four way switches are required to operate a light from eight (8) locations?
a) 6 each 3 way, and 2 each 4 way
b) 2 each 3 way and 6 each 4 way
c) 3 each 3 way and 3 each 4 way
d) None of the above - it cannot be done.
20 When does the Code allow welding of Conduit or couplings?
a) Where raceway risers or cable is not installed within the (lighting) pole, a threaded fitting or nipple shall be brazed or welded to the pole opposite the handhole for the supply connection.
b) The Code does not allow welding of conduit.
c) Conduit couplings can always be welded
d) Conduit can be welded when the AHJ allows it.
e) a and d

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© 2008 Gerald Newton