Article 300: Wiring Methods And Materials

Transcription

1 Part E: Code Book Questions Article 300: Wiring Methods And Materials 1.! Conductors of A.C. or D.C. circuits rated 600 volt or less, shall be permitted to occupy the same! conduit if.! (a)!conductors must have a dividing barrier! (b)!all conductors have a 600 volt insulation rating! (c)! all conductors have an insulation rating equal to at least the maximum circuit voltage! (d)!a.c. and D.C. are not permitted in the same enclosure, raceway or cable 2.! If laid in notches in wood studs, joists, rafters, or other wood members shall be protected! against nails or screws by a steel plate at least 1/16 thick.! (a) EMT! (c) intermediate steel conduit! (b) rigid nonmetallic conduit! (d) flexible conduit 3.! A smoothly rounded insulated surface, or bushing is required on raceways entering boxes,! gutters, etc. if the conduit contains ungrounded conductors AWG or larger.! (a) #6! (c) #2! (b) #4! (d) #1/0 4.! Underground cable installed under a building shall.! (a)!buried at least 6 inches! (b)!not buried more than 12 inches! (c)! be in a raceway that is encased in concrete! (d)!be in a raceway extended beyond the outside walls of a building 5.! Underground service conductors carried up a pole must be protected from mechanical injury to a! height of at least feet.! (a) 8! (c) 12! (b) 9! (d) 15 6.! Rigid conduit buried in an area subject to heavy vehicular traffic shall have a minimum cover of! inches.! (a) 6! (c) 18! (b) 12! (d) 24

2 7.! An underground service installed in PVC and having a 3 concrete envelope shall be buried a! minimum of inches.! (a) 6! (c) 18! (b) 12! (d) 24 8.! A 24 volt landscape lighting system installed with UF cable is permitted with a minimum cover of! inches.! (a) 6! (c) 18! (b) 12! (d) 24 9.! is defined as the shortest distance measured between a point on the top surface of any direct! buried conductor, cable, conduit, or other raceway and the top surface of finished grade.! (a) Depth! (c) Gap! (b) Cover! (d) Soil 10.!Boxes or cabinets having an approved system of organic coatings installed outdoors shall be! marked.! (a) raintight! (c) outdoor type! (b) rainproof! (d) any of these 11.!In areas where the walls are frequently washed, conduit should be mounted with a inch air! space between the wall and the conduit.! (a) 1/8! (c) 3/8! (b) 1/4! (d) 1/2 12.!Where raceways are exposed to widely different temperatures and where condensation is known! to be a problem it shall be, or filled with an approved material to prevent the circulation of! warm air to a colder section.! (a) sealed! (c) grounded! (b) bonded! (d) isolated 13.!All but which of the following shall be mechanically continuous between cabinets, boxes, fittings! or other enclosures or outlets?! (a)!short sections of raceways used to provide support or protection of cable assemblies! (b)!metallic or non-metallic raceways! (c)! cable armors! (d)!cable sheaths

3 14.!The minimum length of free conductor left at each outlet and switch point in a dwelling shall not! be less than inches.! (a) 4! (c) 8! (b) 6! (d) !Raceways shall be installed between outlet, junction or splicing points prior to the! installation of conductors.! (a) partially! (c) straight! (b) complete! (d) tightly 16.!Copper conductors sized at #1/0 AWG, installed in a vertical raceway, shall be supported at! intervals not exceeding feet.! (a) 50! (c) 100! (b) 75! (d) !The Code requires all conductors installed in metal enclosures or raceways to be grouped together! in order to avoid heating the surrounding metal by.! (a) ferro-magnetics! (c) voltage drop! (b) over heating! (d) induction 18.!Where a single copper conductor carrying alternating-current passes through metal with magnetic! properties the inductive effect shall be minimized by.! (a)!cutting slots in the metal between the individual holes conductors pass! (b)!passing all the conductors in the circuit through an insulating wall! (c)! running aluminum instead of copper conductors! (d)!any of the above 19.!Electrical installations in hollow spaces, vertical shafts and ventilation or air-handling ducts shall! be so made that the possible spread of fire or products of combustion will not be.! (a) substantially increased! (c) substantially exposed! (b) allowed! (d) under rated 20.!Which of the following wiring methods may be used inside a duct used for vapor removal and! ventilation of commercial type cooking equipment?! (a) nonmetallic sheathed cable! (c) rigid steel conduit! (b) EMT! (d) none of these

4 21.!Which of the following wiring methods is permitted through an air-conditioning duct?! (a) electrical metallic tubing! (c) non-metallic sheathed cable! (b) rigid nonmetallic tubing! (c) none of these 22.!Electric equipment with a metal enclosure or with a nonmetallic enclosure listed for the use and! having adequate, and associated wiring material suitable for the ambient temperature shall! be permitted to be installed in other space used for environmental air unless prohibited in this! Code.! (a)!fire-resistant! (b)!low-smoke producing characteristics! (c)! both fire-resistant, and low-smoke producing characteristics! (d)!none of these 23.!Suitable covers shall be installed on all boxes, fittings, and similar enclosures to prevent accidental! contact with parts over 600 volts.! (a) energized! (c) electrical! (b) mechanical! (d) none of these 24.!The bending radius for nonshielded cables operating over 600 volts shall not be less than! times the overall diameter.! (a) 6! (c) 10! (b) 8! (d) !Open runs of braid-covered insulated conductors used for over 600 volts shall have a flame! retardant saturant applied to the braid covering after installation unless this protectant is factory! installed. This treated braid covering shall be stripped back a safe distance at conductor terminals,! a distance of not less than for each kilovolt of the conductor-to-ground voltage of the circuit.! (a) 1! (b) 2! (c) 3! (d) 6 26.!A buried cable, rated 4160 volts, requires a minimum cover depth of inches.! (a) 24! (b) 30! (c) 36! (d) !Non-shielded high-voltage underground cables shall be installed in conduit encased in not! less than 3 of concrete.! (a) rigid metal conduit! (c) rigid nonmetallic conduit! (b) intermediate metal conduit! (d) any of these

5 Article 310: Conductors For General Wiring 28.!Conductors AWG and larger shall be stranded when installed in raceways.! (a) #10! (c) #6! (b) #8! (d) #4 29.!Which of the following conductors are not permitted to be connected as parallel?! (a) #1! (c) #2/0! (b) #1/0! (d) #250 kcmil 30.!All of the following about paralleling conductors are true except.! (a) must terminate in the same manner!! (c) must be same length! (b) must be same material!! (d) must be enclosed in the same raceway 31.!Differences in inductive reactance and unequal division of current can be minimized by choice! of.! (a) orientation of conductors! (c) choice of materials! (b) methods of construction! (d) all of the above 32.!What is the minimum size conductor permitted for general wiring under 600 volts?! (a) #12 copper! (c) #14 copper! (b) #12 aluminum! (d) #14 aluminum 33.!Solid dielectric insulated conductors operated above 2000 volts in permanent installations shall! have ozone-resistant insulation and shall be.! (a) covered! (c) shielded! (b) protected! (d) surface mounted 34.!Which of the following insulated conductors can be used in wet locations?! (a) MTW! (c) asbestos! (b) THHN! (d) varnished cambric 35.!No conductor shall be used in such a manner that its operating temperature exceeds that! designated for the type of conductor involved.! (a) covered! (c) insulated! (b) protected! (d) wiring

6 36.!The temperature rating of a conductor is the maximum temperature, at any location along its! length, that the conductor can withstand over a prolonged time period without.! (a) tripping the breaker! (c) short circuiting! (b) serious degradation! (d) a ground fault 37.!The principal determinants of operating temperature are.! (a)!ambient temperature! (b)!heat generated internally in the conductor as the result of load current flow! (c)! adjacent load-carrying conductors! (d)!all of the above 38.!Insulated wires shall be marked or tagged with which of the following?! (a) maximum rated voltage! (c) manufacturer s name, trademark! (b) proper type letters! (d) all of the above 39.!Surface marking of conductors and cables shall be durably marked on the surface at intervals not! exceeding inches.! (a) 6! (c) 18! (b) 12! (d) !The letter suffix shall indicates two insulated conductors laid parallel within an outer! nonmetallic covering.! (a) D! (c) R! (b) M! (d) N 41.!Thermoplastic insulation may stiffen at temperatures colder than minus requiring care be! exercised during installation at such temperatures.! (a) -5 C! (c) -15 C! (b) -10 C! (d) -30 C 42.!Type MTW insulation would be used for.! (a) switchboards only! (c) feeders only! (b) machine tool wiring! (d) fixtures

7 43.!THW conductors used to connect electric discharge lighting equipment has a maximum operating! temperature of C.! (a) 60 C! (c) 90 C! (b) 75 C! (d) any of these 44.!The ampacity of a #8 XHHW copper conductor in a wet location is.! (a) 55 amps! (c) 45 amps! (b) 50 amps! (d) 40 amps 45.!All of the following sizes of solid aluminum conductors can be made of aluminum alloy except?! (a) #14 AWG! (c) #10 AWG! (b) #12 AWG! (d) #8 AWG 46.!When more than one calculated or tabulated ampacity could apply for a given circuit length, the! value shall be used.! (a) lowest! (c) highest! (b) average! (d) none of these 47.!Where single conductors or multiconductor cables are stacked or bundled longer than! without maintaining spacing and are not installed in raceways, the ampacity of each conductor! shall be reduced.! (a) 12 inches! (c) 20 inches! (b) 18 inches! (d) 24 inches 48.!Where the number of current-carrying conductors in a raceway is seven, the individual ampacity! of each conductor shall be reduced.! (a)!to 70% due to the number of conductors! (b)!to 80% if they are continuous loads! (c)! to 90% due to the number of conductors! (d)!neither apply if the ambient temperature is below 30 C or 86 F 49.!A conduit nipple contains six #8 THW copper current-carrying conductors. The ampacity of each! conductor would be amps.! (a) 50! (c) 35! (b) 40! (d) 24

8 50.!What is the ampacity of four #6 THW copper current-carrying conductors enclosed in schedule 80! PVC conduit, 8 feet in length entering a trench?! (a) 65 amps! (c) 44 amps! (b) 52 amps! (d) 40 amps 51.!When bare grounded conductors are used with insulated conductors, their ampacities are limited! to.! (a) 60 C! (c) 90 C! (b) 75 C! (d) that permitted for the adjacent insulated conductors 52.!When balancing a multiwire (three-wire, single-phase) circuit the neutral conductor.! (a) should carry only the unbalance current!! (c) should carry the sum of the currents! (b) is used only for grounding purposes!! (d) none of these 53.!A three-wire, 120/240 volt, single-phase, 200 amp service for a dwelling unit requires THW! copper conductors.! (a) #4/0! (c) #2/0! (b) #3/0! (d) #1/0 54.!Which of the following is/are true about equipment grounding conductors?! (a)!they do not count as a current-carrying conductors.! (b)!bare, covered or insulated shall be permitted.! (c)! They count as conductors when calculating conduit fill.! (d)!all of these 55.!The ampacity of conductors are derated (reduced) when the ambient temperature! exceeds.! (a) 30 F! (c) 86 F! (b) 72 F! (d) 104 F Article 312: Cabinets, Cutout Boxes, And Meter Enclosures 56.!Cabinets, cutout boxes, and meter socket enclosures installed in wet locations shall be and! shall be mounted so there is at least 1/4 airspace between the enclosure and the wall.! (a) raintight! (c) waterproof! (b) weatherproof! (d) rainproof

9 57.!Nonmetallic enclosures shall be permitted to be installed airspace on a concrete, masonry! tile, or similar wall.! (a) without! (c) with 1/8! (b) with 1-1/4! (d) 1/16 58.!The minimum wire-bending space for a #2 AWG conductor at terminals is.! (a) 2! (c) 3-1/2! (b) 2-1/2! (d) 4 59.! is the distance measured along the enclosure wall from the axis of the centerline of the! terminal to a line passing through the center of the opening in the enclosure.! (a) Offset! (c) Center point! (b) Radius! (d) none of these 60.!A #250 kcmil copper conductor leaves through the wall opposite its terminal. The minimum! bending space would be.! (a) 4! (c) 6-1/2! (b) 4-1/2! (d) 8-1/2 61.!A cabinet or cutout box if constructed of sheet steel, the metal thickness shall not be less than! inch uncoated.! (a) 0.053! (c) 0.040! (b) 0.503! (d) !There shall be an air space of at least between walls, back, gutter partition, if of metal, or! door of any cabinet, or cut out box and nearest exposed current-carrying parts of devices mounted! within the cabinet where the voltage exceeds 251 volts.! (a) inches! (c) 1.00 inches! (b) inches! (d) inches 63.!Cabinets and cutout boxes shall be deep enough to allow the closing of the doors when! ampere branch circuit panelboard switches are in any position; when combination cutout switches! are in any position; or when other single throw switches are opened as far as their construction! permits.! (a) 15! (c) 30! (b) 20! (d) 100

10 64.!Cabinets and cutout boxes that contain devices or apparatus connected within the cabinet or box! to more than conductors, including those of branch circuits, meter loops, feeder circuits,! power circuits, and similar circuits, but not including the supply circuit or continuation thereof,! shall have back wiring spaces or one or more side wiring spaces, side gutters, or wiring! compartments.! (a) 8! (c) 21! (b) 10! (d) 30 Article 314: Outlet, Device, Pull-Junction Boxes, Conduit Bodies, Fittings, Handholes 65.! boxes shall not be used where conduits or connectors requiring the use of locknuts or! bushings are to be connected to the side of the box.! (a) Round! (c) Device! (b) Shallow! (d) Gang 66.!The volume of a wiring enclosure (box) shall be the total volume of the, and, where used, the! space provided by plaster rings, domed covers, extension rings, and so forth, that are marked with! their volume in cubic inches, or are from boxes the dimensions listed in Table (A).! (a) enclosure! (c) assembled sections! (b) outlet! (d) none of these 67.!When counting the number of conductors in a box, a conductor running through the box (loop! wire) is counted as one conductor if not more than inches long.! (a) 12! (c) 14! (b) 13! (d) none of these 68.!The number of #12 conductors permitted in a 3 x 2 x 1-1/2 deep device box is.! (a) 6! (c) 4! (b) 5! (d) 3 69.!The minimum volume of a 3 x 2 x 2 device box is cubic inches.! (a) 12.5! (c) 10.0! (b) 14.0! (d) !An installation requires a device box with a capacity of cubic inches. What is the minimum! size box allowed?! (a) 3 x 2 x 1-1/2! (c) 3 x 3 x 2! (b) 3 x 2 x 2! (d) 3 x 2 x 2-1/4

11 71.!Conduit bodies shall have a cross-sectional area at least the largest conduit to which they are! connected (#6 conductors and smaller).! (a) once! (c) four times! (b) twice! (d) five times 72.!Where nonmetallic-sheathed cable is used, the cable assembly, including the sheath shall extend! into the box not less than.! (a) 1! (c) 1/2! (b) 3/4! (d) 1/4 73.!Where nonmetallic sheathed cable is used with boxes no larger than mounted in walls or! ceilings and where the cable is fastened within 8 inches of the box, securing the cable to the box! shall not be required.! (a) 1-1/4 x 4! (c) 2-1/4 x 4! (b) 2 x 4! (d) 2-1/2 x 4 74.!The front edge of a switch box installed in a tiled wall can be recessed maximum of inches! behind the finished wall.! (a) 1/4! (c) 1/2! (b) 3/8! (d) not at all 75.!The front edge of an outlet box in combustible walls or ceilings shall be with the finished! surface.! (a) set back a minimum of 1/4! (c) set back a minimum of 1/2! (b) set back a minimum of 1/8! (d) flush with the finished surface 76.!Plaster, drywall or plasterboard surfaces that are broken or incomplete shall be repaired so there! will be no gaps or open spaces greater than inch at the edge of the fitting or box.! (a) 1/8! (c) 3/16! (b) 1/6! (d) 1/4 77.!Wood braces used in structural mounting of boxes shall have a cross-section not less than! nominal.! (a) 3/4 x 1-1/2! (c) 1 x 2! (b) 1 x 1-1/2! (d) 3/4 x 2

12 78.!Enclosures supported by suspended ceiling systems shall be fastened to the framing member by! mechanical means such as.! (a) clips identified for use! (c) rivets and bolts! (b) screws! (d) any of these 79.!A 76 cubic inch junction box, has two 3/4 rigid conduits entering the bottom of the box, the! conduits are supported 36 from the box. Which of the following is a correct statement:! (a)!this box may be supported by wood braces of not less than 3/4 x 1 1/2! (b)!this box must be rigidly supported by a structural member! (c)! this box is not required to have any other support! (d)!this box may be supported by nails if located within 2 of the back or ends 80.!The internal depth of outlet boxes intended to enclose flush devices shall be at least.! (a) 1/2! (c) 15/16! (b) 7/8! (d) 1-1/2 81.!Of the following, box may be used for a floor receptacle.! (a)!a 4-11/16 x 1-1/4 square metal box with device ring listed for the purpose! (b)!a 3 x 2 x 2-1/2 metal device box with device ring listed for the purpose! (c)! a box listed specifically for this application! (d)!none of these 82.!Angle-pull dimensional requirements apply to junction boxes only when the size of conductor is! equal to or larger than.! (a) #3/0! (c) #4! (b) #1/0! (d) #6 83.!In straight pulls, the length of the box shall be not less than times the trade diameter of the! largest raceway.! (a) 4! (c) 8! (b) 6! (d) !Where a permanent barrier is installed in a pull box each section is considered as.! (a) permanent barriers are not allowed!! (c) 60% of the box! (b) a separate box!! (d) the same box

13 85.!What is the minimum thickness of steel box (dimensions 6 x 4 x 3-1/4 )?! (a).0625! (c) 15 MSG! (b).0747! (d) 16 MSG 86.!A means shall be provided in each metal box for the connection of an equipment grounding! conductor. The means shall be permitted to be.! (a) a tapped hole! (c) a screw used to mount the box! (b) the cover screw! (d) any of these 87.!For straight pulls, the length of the box shall be not less than the outside diameter, over! sheath, of the largest conductor or cable entering the box on systems over 600 volts.! (a) 8 times! (c) 36 times! (b) 6 times! (d) 48 times 88.!The distance between a cable or conductor entry and its exit from the box shall be not less than! times the outside diameter, over sheath, of that cable or conductor. (1000 volt system)! (a) 6! (c) 36! (b) 18! (d) !Covers for pull and junction boxes over 600 volts shall be permanently marked.! (a) Caution! (c) Do Not Open! (b) Danger! (d) Danger-High-Voltage Keep Out Article 320: Armored Cable (Type AC) 90.!Type AC (armored cable) shall be permitted.! (a) in exposed and concealed work! (c) in dry locations! (b) in cable trays! (d) all of the above 91.!Exposed runs of AC cable shall closely follow the surface of the building or of running boards.! Exposed runs shall also be permitted to be installed on the underside of joists.! (a) where supported at each joist!! (c) shall be securely fastened in place! (b) where subject to physical damage!! (d) all of the above

14 92.!Type AC cable installed in thermal insulation shall have conductors rated at. The ampacity! of cable installed in these applications shall be that of 60 C conductors.! (a) 60 C! (c) 90 F! (b) 75 C! (d) 194 F 93.!Cables of the AC type shall have an armor of and shall have an internal bonding strip of! copper or aluminum in intimate contact with the armor for its entire length.! (a) aluminum! (c) flexible metal tape! (b) copper! (d) bonding tape Article 322: Flat Cable Assemblies (FC) 94.!Type, a flat cable assembly, is an assembly of parallel conductors formed integrally with an! insulating material web specifically designed for field installation in surface metal raceway.! (a) FCC! (c) TC! (b) FC! (d) SNM 95.!Flat cable (FC) assemblies may be installed.! (a)!for small power loads outdoors, not subject to physical damage! (b)!as tap devices for lighting and small appliances! (c)! for small power loads in hoistways! (d)!any of these 96! When a flat cable assembly is installed less than feet from the floor, or platform, it shall be! protected by a cover identified for the use.! (a) 8! (c) 12! (b) 10! (d) !Tap devices used in FC assemblies shall be rated at not less than amps.! (a) 15! (c) 30! (b) 20! (d) !The terminal block for the termination of flat cable assemblies shall have distinctive and durable! marking for color or word coding. The grounded conductor section shall have a white marking or! other suitable designation. The next adjacent section of the terminal block shall have a! marking.! (a) black! (c) red! (b) blue! (d) green