Page | 1
NEC QUESTIONS WITH DETAILED
VERIFIED ANSWERS
A _________ barrier shall be requied if the space between the resistors
and reactors and any combustible material
470.3 Ans: thermal
The voltage computed on the basis of 2 volts per cell for the lead-acid
type and ____________ volts per cell for the alkali type.
480.2 Ans: 1.2
Frames of switchgear and control assemblies shall be _____________.
490.36 Ans: grounded
A circuit which any arc or thermal effect produced under intended
operating conditions of the equipment is not capable.
500.2 Ans: Non-incendive circuit
Electrical equipment immersed in a protective liquid in such a way that an
explosive atmosphere the may be above the liquid or outside the
enclosure cannot be ignited.
500.2 Ans: oil immersion
The interior of spray booths and areas in the vicinity of spraying anf
painting are in _______________.
500.5 (B)(1)(2) Ans: Class I - Division 1
Class II locations are those tha are hazardous because of the presence of
________________.
500.5 (C) Ans: combustible dust
, Page | 2
Flammable gas, flammable liquid-produced vapor, or combustible liquid-
produced vapor mixed with air the may burn is in ______________
material that is hydrogen
500.6 (2) Ans: Class 1 - Group B
Protective techniques shall be acceptable for electrical and electronic
equipment in hazardous (classified) sealed locations.
500.7 (J) Ans: Class 1 - Division 2
Class II equipment shall be marked to show the class, group and
___________ temperature.
500.7 (4) Ans: operating
All threaded conduit shall be made __________ to prevent sparking
when fault current flows through the conduit system and to ensure the
explosion proof of flameproof integrity of the conduit system where
applicable.
500.7 (e) Ans: Wrench-tight
To facilitate replacements, process control instruments shall be permitted
to be connected through flexible cord, the power-supply cord shall not
exceed __________.
501.105 Ans: 3
Threaded rigid metal conduit or threaded steel in ________ locations
shall be used for the last 24 inches of the underground run to emergence.
501.10 Ans: Class I - Division 1
Seals in conduit and cable, sealing compound be used in type MI cable
termination fittings to exclude ____________ and other fluids from the
cable insulation.
501.15 Ans: Moisture
, Page | 3
In Class I - Division 1 locations, the entry shall be metric designator
trade size ___________ or larger and the enclosure contains terminals
splices, ot taps.
501.15 Ans: 2
Counduit seals shall be installed within __________ from the enclosure.
501.15 (1) Ans: 18
In each conduit run passing thru Class 1 - Division 2 locations into an
unclassified location shall be _____________ at the boundary.
501.15 Ans: Seal
Conduit syatems passing from an enclosure or room that is unclasssified
as a result of pressurization into a _______________ location shall not
require a seal at the boundary.
501.15 (2) Ans: Class I - Division 2
In a completed seral, the minimum thickness of the sealing shall in no
case be less than __________ inch.
501.15 (c)(3) Ans: 5/8
Cable passing from an enclosure or room that is unclassified as a result of
type z pressurization into a ____________ shall not require a seal at the
boundary.
501.17 (e) Ans: Class I - Division 2
Elecctrically heated utilization equipment shall not exceed _________
percent of the ignition temperature in degree of the gas or vapor.
501.135 Ans: 80
In industrial establishments with limited public access, where the
conditins of maintance and supervision ensure that only qualified persons
service the installation of type ________ cable shall be permitted.
NEC QUESTIONS WITH DETAILED
VERIFIED ANSWERS
A _________ barrier shall be requied if the space between the resistors
and reactors and any combustible material
470.3 Ans: thermal
The voltage computed on the basis of 2 volts per cell for the lead-acid
type and ____________ volts per cell for the alkali type.
480.2 Ans: 1.2
Frames of switchgear and control assemblies shall be _____________.
490.36 Ans: grounded
A circuit which any arc or thermal effect produced under intended
operating conditions of the equipment is not capable.
500.2 Ans: Non-incendive circuit
Electrical equipment immersed in a protective liquid in such a way that an
explosive atmosphere the may be above the liquid or outside the
enclosure cannot be ignited.
500.2 Ans: oil immersion
The interior of spray booths and areas in the vicinity of spraying anf
painting are in _______________.
500.5 (B)(1)(2) Ans: Class I - Division 1
Class II locations are those tha are hazardous because of the presence of
________________.
500.5 (C) Ans: combustible dust
, Page | 2
Flammable gas, flammable liquid-produced vapor, or combustible liquid-
produced vapor mixed with air the may burn is in ______________
material that is hydrogen
500.6 (2) Ans: Class 1 - Group B
Protective techniques shall be acceptable for electrical and electronic
equipment in hazardous (classified) sealed locations.
500.7 (J) Ans: Class 1 - Division 2
Class II equipment shall be marked to show the class, group and
___________ temperature.
500.7 (4) Ans: operating
All threaded conduit shall be made __________ to prevent sparking
when fault current flows through the conduit system and to ensure the
explosion proof of flameproof integrity of the conduit system where
applicable.
500.7 (e) Ans: Wrench-tight
To facilitate replacements, process control instruments shall be permitted
to be connected through flexible cord, the power-supply cord shall not
exceed __________.
501.105 Ans: 3
Threaded rigid metal conduit or threaded steel in ________ locations
shall be used for the last 24 inches of the underground run to emergence.
501.10 Ans: Class I - Division 1
Seals in conduit and cable, sealing compound be used in type MI cable
termination fittings to exclude ____________ and other fluids from the
cable insulation.
501.15 Ans: Moisture
, Page | 3
In Class I - Division 1 locations, the entry shall be metric designator
trade size ___________ or larger and the enclosure contains terminals
splices, ot taps.
501.15 Ans: 2
Counduit seals shall be installed within __________ from the enclosure.
501.15 (1) Ans: 18
In each conduit run passing thru Class 1 - Division 2 locations into an
unclassified location shall be _____________ at the boundary.
501.15 Ans: Seal
Conduit syatems passing from an enclosure or room that is unclasssified
as a result of pressurization into a _______________ location shall not
require a seal at the boundary.
501.15 (2) Ans: Class I - Division 2
In a completed seral, the minimum thickness of the sealing shall in no
case be less than __________ inch.
501.15 (c)(3) Ans: 5/8
Cable passing from an enclosure or room that is unclassified as a result of
type z pressurization into a ____________ shall not require a seal at the
boundary.
501.17 (e) Ans: Class I - Division 2
Elecctrically heated utilization equipment shall not exceed _________
percent of the ignition temperature in degree of the gas or vapor.
501.135 Ans: 80
In industrial establishments with limited public access, where the
conditins of maintance and supervision ensure that only qualified persons
service the installation of type ________ cable shall be permitted.
