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NEC CODE NEC 2023

NEC 500 hazardous locations

Free online theory quiz test on hazardous locations (NEC 500)

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Frequently Asked Questions

Yes — free, no signup required. Each question links to the relevant NEC article so you can study the code directly.

The National Electrical Code (NFPA 70) is the benchmark standard for safe electrical installation in the US. It is updated every 3 years by the NFPA.

Study the edition adopted by your state. As of 2025, most states use the 2020 or 2023 NEC. These tests are written to the 2023 edition.

The most tested articles are 100 (Definitions), 200–250 (Wiring & Grounding), 300–314 (Wiring Methods), 400–411 (Conductors), 430 (Motors), and 700–701 (Emergency Systems).

8

Questions

12 min

Time

70%

Pass

Timer starts immediately. Progress is auto-saved.

NEC 500 hazardous locations — Question List

Question 1: The combustible dust may be present in which of the following locations?

class I
class II
class III

Question 2: In Class I Division 2 location the flammable substances are likely to be under normal operating conditions.

True
False

Question 3: Which of the following raceways cannot be used in class I division 1 location?

RMC
Steel IMC
Concrete encased PVC
Gasketed enclosed wire ways

Question 4: When a conduit run passing from a Class I , Division 2 location into a unclassified location must have seal located with …………….. Feet of the boundary.

5 feet
10 feet
8 feet
6 feet

NEC Reference: NEC 501.15(B)(2)

Question 5: Dispensing devices for liquefied petroleum gas shall be located not less than …………….. feet from any dispensing device for Class I liquids

5 feet
8 feet
4 feet
6 feet

NEC Reference: NEC 514.3(B)(2)

Question 6: <strong></strong>In Class II Division I locations, the enclosures for circuit breakers, motor controllers, fuses shall be ……………..

dust tight
water proof
fire proof

NEC Reference: NEC 502.115(B)

Question 7: In class I division 2 location, unless it is specified the cross sectional area of the conductors permitted in a seal shall not exceed …………. Percentage of a cross sectional area of RMC.

25 %
50 %
75 %
10 %

NEC Reference: NEC 501.15(C)(6)

Question 8: Tank storage installations inside buildings below grade level are classified as ……………….

Class I , Zone 1
Class II , Zone 1
Class I , Zone 2
Class II , Zone 2

NEC Reference: NEC 515.3

EXAM CARD NEC CODE

Questions8

Time limit12 min

Pass score70%

Code editionNEC 2023

DifficultyIntermediate

Timer starts immediately. Progress is auto-saved.