NEC Comprehensive Questions
(Frequently Tested) with Verified
Answers Graded A+
90.1 (A) Practical Safeguarding - Answer: The purposes of this code is the practical safeguarding
of person and property from hazards arising from the use of electricity.This code is not intended
as design specifications or an instruction manual for untrained persons.
90.1 (B) Adequacy. - Answer: This code Contains provisions that are considered necessary for
safety. Compliance there with and proper maintenance result in installation that is essentially
free From hazard but not necessarily efficient, convenient, or adequate for good service or
future expansion of electrical use.
90.1 (C) Relation to Other Internal Standard - Answer: TheRequirements in this code address is
the fundamental principles of protection for safety Contained in section 131 of international
electrotechnical commission standards 60364-1 Section 131 electrical installation of buildings.
90.2 Scope (A) Covered - Answer: This code Covers the installation and removal of electrical
conductors, equipment, and raceways; an optical fiber cables for the following:
(1) Public and private premises, including buildings, structures, mobile homes, recreation of
vehicles, and floating buildings.
(2) Yard, lots, parking lots, Carnivores, and industrial substations.
(3) Installation of conductors and equipment that connect to the supply of electricity.
(4) Installation used by the electric utility, Search office as Office building, where houses,
garages, machine shops, and re-creation of buildings, that are not an integral part of a
generation plants, substation, or control center.
(5) Installation supplying shore power to ships and watercraft in Marina's in boat Yard including
monitoring leakage current.
(6) Installations used to export electricity power from vehicles to premises wiring or four by
directional current flow.
,90.2 Scope (B) Not Covered - Answer: (1) Installations in ships, water crafts other than floating
buildings railway, rolling stock, aircraft, automotive vehicles Other than mobile homes and
recreational vehicles.
(2) Installations underground in mines and self-propelled mobile surface mining machinery and
its attendant electrical training cable.
(3) Installations of railway for generations, transformations, transmissions, energy storage, or
distribution of power used exclusively for operation on rolling stock or installation used
exclusively for signaling and communication purposes.
(4) Installations of communications equipment under the exclusive control of communication
utilities located outdoors or in building space is used exclusively for such installations.
(5) Installations under the exclusive control of an electric and utilities were such installations...
(a-d)
90.2 (C) Special permission - Answer: The Authority having jurisdiction for enforcing this code
may grant exception for the installation of conductors and equipment that are not under
exclusive control over electric utilities and are used to connect electric utility supply system to
the service conductor of the premises served, provided search installations are outside a
building or structure, or terminate inside at a readily accessible location nearest the point of
entrance of the service conductor.
90.3 Code Arrangement - Answer: This code If divided into the introduction and nine chapters
as shown in figure 19.3 chapter 1, 2, 3, and four apply "GENERALLY". Chapters 5,6 and 7 applied
to "special occupancies, special equipment, or other special conditions in May supplement or
modify the requirements in chapter 1-7".
90.4 Enforcement - Answer: This code is intended to be a suitable for mandatory applications
by government total body use that exercise legal jurisdiction over electrical installations,
including signaling and communication systems, and for the use by insurance inspectors. The
authority having jurisdiction for enforcement of code has the responsibility for making
interpretations of the rules for deciding on the approval of equipment and materials, and for
the granting the special permission contemplated in numbers of the rules.
,By special permission, the authority having jurisdiction may waive specific requirements in this
cold or permanent alternative methods where it is assured that equivalent objectives can be
achieved by establishing and maintaining effective safety.
This code may require new products, construction, or materials that may not yet be available at
the time the code is adopted. In such event, the authority having jurisdiction may permit the
use of the products, constructions, or materials that comply with the most recent previous
edition of this code adopted by the jurisdiction.
90.5 (A) Mandatory Rules - Answer: Mandatory rules of this code Are those that identify
actions that are specifically required or prohibited and are characterized by the use of the term
"shall" or "shall not".
90.5 (B) Permissive Rule - Answer: Permissive Rules of this code are those that identify actions
that are allowed but not required or normal used to describe actions or alternative methods
and are characterized by the use of the term "shall be permitted" or "shall not be required".
90.5 (C) Explanatory Material - Answer: Explanatory Material, such as references to other
standards, references to related sections of this code, or information related to a code rule, is
included in this code in form of informational notes. Search Notes our informational only enter
not enforce the rule as requirements of this code.
90.5 (D) Informative Annexes - Answer: Non-Mandatory information relative to the use of the
NEC is provided in informative annexes. informative annexes are not part of this Code of the
enforceable requirements of the NEC, but are included for information purposes only.
90.6 Formal Interpretations - Answer: To promote uniformity relative of interpretation and
application of this code, formal interpretation procedures have been established and are found
in that NFPA regulations governing committee projects.
, 90.7 Examination of Equipment for Safety - Answer: For specific items of equipment and
materials referred to in this code, examination for safety made under standard conditions
provide a basis for formal approval where the record is made generally available through
Promulgation by organizations properly equipped and qualified for experimental testing,
Inspections of the run of good at factories, and services-value determination through
inspections.ThisAvoid the necessity repetition of examinations five different examiners,
frequently with Inadequate facilities for such work, and the confusion that would result from
conflicting reports on the suitability of devices and materials examine for a given purpose.
90.8 Wiring Planing (A) Future Expansion and Convenience. - Answer: Plans and Specifications
that provide ample Space in raceways, spare raceways, and additional spaces allow for future
increases in electrical power and communication circuits. Distribution centers located in readily
accessible locations provide convenience and safety of operation.
90.8 (B) Number of Circuits in Enclosures. - Answer: It is Elsewhere provided in this code that
the number of circuits confined in a single enclosure be very restricted. Limiting the number of
circuits in a single enclosure minimizes the fact from short Circuit or ground fault.
90.9 Units of Measurement (A) Measurement System Of Prefrence - Answer: For the Purpose
of this code Metric unit of Measurements are Are in accordance with the modernize metric
systemKnown as the international system of units (SI).
90.9 (B) Dual system of units. - Answer: SI unit shall appear First, And inch-pound units shall
immediately follow in parentheses. Conversion from inch-pound units to SI units shall be based
on hard conversion and shall be permitted to use soft conversion.
90.9 (C) Permitted uses of soft conversions. - Answer: The cases given in 90.9(c) (1) through (c)
(4) shall not be required to use hard conversion and shall be permitted to use soft conversion.
(1)Trade Sizes
Where are the actual measurements size of a product is not the same as nominal size, trade size
designators shall be used rather than dimensions. Trade practices shall be followed in all cases.
(2) Extracted Material
(Frequently Tested) with Verified
Answers Graded A+
90.1 (A) Practical Safeguarding - Answer: The purposes of this code is the practical safeguarding
of person and property from hazards arising from the use of electricity.This code is not intended
as design specifications or an instruction manual for untrained persons.
90.1 (B) Adequacy. - Answer: This code Contains provisions that are considered necessary for
safety. Compliance there with and proper maintenance result in installation that is essentially
free From hazard but not necessarily efficient, convenient, or adequate for good service or
future expansion of electrical use.
90.1 (C) Relation to Other Internal Standard - Answer: TheRequirements in this code address is
the fundamental principles of protection for safety Contained in section 131 of international
electrotechnical commission standards 60364-1 Section 131 electrical installation of buildings.
90.2 Scope (A) Covered - Answer: This code Covers the installation and removal of electrical
conductors, equipment, and raceways; an optical fiber cables for the following:
(1) Public and private premises, including buildings, structures, mobile homes, recreation of
vehicles, and floating buildings.
(2) Yard, lots, parking lots, Carnivores, and industrial substations.
(3) Installation of conductors and equipment that connect to the supply of electricity.
(4) Installation used by the electric utility, Search office as Office building, where houses,
garages, machine shops, and re-creation of buildings, that are not an integral part of a
generation plants, substation, or control center.
(5) Installation supplying shore power to ships and watercraft in Marina's in boat Yard including
monitoring leakage current.
(6) Installations used to export electricity power from vehicles to premises wiring or four by
directional current flow.
,90.2 Scope (B) Not Covered - Answer: (1) Installations in ships, water crafts other than floating
buildings railway, rolling stock, aircraft, automotive vehicles Other than mobile homes and
recreational vehicles.
(2) Installations underground in mines and self-propelled mobile surface mining machinery and
its attendant electrical training cable.
(3) Installations of railway for generations, transformations, transmissions, energy storage, or
distribution of power used exclusively for operation on rolling stock or installation used
exclusively for signaling and communication purposes.
(4) Installations of communications equipment under the exclusive control of communication
utilities located outdoors or in building space is used exclusively for such installations.
(5) Installations under the exclusive control of an electric and utilities were such installations...
(a-d)
90.2 (C) Special permission - Answer: The Authority having jurisdiction for enforcing this code
may grant exception for the installation of conductors and equipment that are not under
exclusive control over electric utilities and are used to connect electric utility supply system to
the service conductor of the premises served, provided search installations are outside a
building or structure, or terminate inside at a readily accessible location nearest the point of
entrance of the service conductor.
90.3 Code Arrangement - Answer: This code If divided into the introduction and nine chapters
as shown in figure 19.3 chapter 1, 2, 3, and four apply "GENERALLY". Chapters 5,6 and 7 applied
to "special occupancies, special equipment, or other special conditions in May supplement or
modify the requirements in chapter 1-7".
90.4 Enforcement - Answer: This code is intended to be a suitable for mandatory applications
by government total body use that exercise legal jurisdiction over electrical installations,
including signaling and communication systems, and for the use by insurance inspectors. The
authority having jurisdiction for enforcement of code has the responsibility for making
interpretations of the rules for deciding on the approval of equipment and materials, and for
the granting the special permission contemplated in numbers of the rules.
,By special permission, the authority having jurisdiction may waive specific requirements in this
cold or permanent alternative methods where it is assured that equivalent objectives can be
achieved by establishing and maintaining effective safety.
This code may require new products, construction, or materials that may not yet be available at
the time the code is adopted. In such event, the authority having jurisdiction may permit the
use of the products, constructions, or materials that comply with the most recent previous
edition of this code adopted by the jurisdiction.
90.5 (A) Mandatory Rules - Answer: Mandatory rules of this code Are those that identify
actions that are specifically required or prohibited and are characterized by the use of the term
"shall" or "shall not".
90.5 (B) Permissive Rule - Answer: Permissive Rules of this code are those that identify actions
that are allowed but not required or normal used to describe actions or alternative methods
and are characterized by the use of the term "shall be permitted" or "shall not be required".
90.5 (C) Explanatory Material - Answer: Explanatory Material, such as references to other
standards, references to related sections of this code, or information related to a code rule, is
included in this code in form of informational notes. Search Notes our informational only enter
not enforce the rule as requirements of this code.
90.5 (D) Informative Annexes - Answer: Non-Mandatory information relative to the use of the
NEC is provided in informative annexes. informative annexes are not part of this Code of the
enforceable requirements of the NEC, but are included for information purposes only.
90.6 Formal Interpretations - Answer: To promote uniformity relative of interpretation and
application of this code, formal interpretation procedures have been established and are found
in that NFPA regulations governing committee projects.
, 90.7 Examination of Equipment for Safety - Answer: For specific items of equipment and
materials referred to in this code, examination for safety made under standard conditions
provide a basis for formal approval where the record is made generally available through
Promulgation by organizations properly equipped and qualified for experimental testing,
Inspections of the run of good at factories, and services-value determination through
inspections.ThisAvoid the necessity repetition of examinations five different examiners,
frequently with Inadequate facilities for such work, and the confusion that would result from
conflicting reports on the suitability of devices and materials examine for a given purpose.
90.8 Wiring Planing (A) Future Expansion and Convenience. - Answer: Plans and Specifications
that provide ample Space in raceways, spare raceways, and additional spaces allow for future
increases in electrical power and communication circuits. Distribution centers located in readily
accessible locations provide convenience and safety of operation.
90.8 (B) Number of Circuits in Enclosures. - Answer: It is Elsewhere provided in this code that
the number of circuits confined in a single enclosure be very restricted. Limiting the number of
circuits in a single enclosure minimizes the fact from short Circuit or ground fault.
90.9 Units of Measurement (A) Measurement System Of Prefrence - Answer: For the Purpose
of this code Metric unit of Measurements are Are in accordance with the modernize metric
systemKnown as the international system of units (SI).
90.9 (B) Dual system of units. - Answer: SI unit shall appear First, And inch-pound units shall
immediately follow in parentheses. Conversion from inch-pound units to SI units shall be based
on hard conversion and shall be permitted to use soft conversion.
90.9 (C) Permitted uses of soft conversions. - Answer: The cases given in 90.9(c) (1) through (c)
(4) shall not be required to use hard conversion and shall be permitted to use soft conversion.
(1)Trade Sizes
Where are the actual measurements size of a product is not the same as nominal size, trade size
designators shall be used rather than dimensions. Trade practices shall be followed in all cases.
(2) Extracted Material
