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NEC 2020 Code Questions Practice Test 17

Free NEC 2020 practice test with 30 questions on hazardous locations, pools, signs, heating equipment, and key NEC definitions. Plain-English questions with full explanations.

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How to Use This Practice Test

This NEC 2020 Code Questions Practice Test 17 has 30 questions with detailed answers and NEC references. Take the full test, review every wrong answer, and look up the NEC article it references before moving on.

Tip: Mixed-format test — questions jump between topics just like the real exam. Don't spend more than 90 seconds on any one question.

Topics covered: All NEC chapters — branch circuits, grounding, conductors, wiring methods, motors, and more.
Passing score: Aim for 80%+ consistently before scheduling your exam.
Questions: 30 multiple-choice, one correct answer each

Questions

45 min

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70%

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NEC 2020 Code Questions Practice Test 17 — Question List

Question 1: The main wiring method for a Class I, Division 1 hazardous location is:

Threaded rigid metal conduit
Open knob-and-tube wiring
Standard NM cable
Bare wire in open air

NEC Reference: NEC 501.10(A)

Question 2: A conduit run from a Class I, Division 2 space into an unclassified space needs a seal within what distance of the boundary?

5 feet
10 feet
20 feet
50 feet

NEC Reference: NEC 501.15

Question 3: Equipment used in a hazardous location must be approved for the specific class and:

Group and properties of the hazard
Color of the building
Nothing else
The installer's preference

NEC Reference: NEC 500.8(A)

Question 4: Intrinsically safe conductors are identified by the color:

Blue
Red
Black
Brown

NEC Reference: NEC 504.80(C)

Question 5: An electric sign needs a disconnect that is within sight of the sign, or if not, it must be:

Lockable in the open position
Left unlocked always
Removed entirely
Not required at all

NEC Reference: NEC 600.6

Question 6: Electric signs and outline lighting must generally be:

Listed
Homemade
Exempt from all rules
Approved by the owner only

NEC Reference: NEC 600.3

Question 7: A portable sign in a dry location is supplied by a cord no longer than:

8 feet
12 feet
16 feet
20 feet

NEC Reference: NEC 600.10(D)(2)

Question 8: The smallest conductor permitted for pool bonding is generally:

12 AWG
10 AWG
8 AWG
6 AWG

NEC Reference: NEC 680.26

Question 9: An outlet supplying a pool pump motor, whether by cord or direct connection, must be provided with:

GFCI protection
AFCI protection only
No protection
Overvoltage protection only

NEC Reference: NEC 680.21(C)

Question 10: Wiring methods at a marina must resist the wet, salty environment, and generally include:

Rigid metal conduit or PVC
Standard indoor NM cable
Bare wire in open air
No wiring method restrictions apply

NEC Reference: NEC 555.15

Question 11: The overall length of a mobile home power supply cord must not be more than:

20 feet
36 1/2 feet
50 feet
There is no limit

NEC Reference: NEC 550.10(J)

Question 12: Which of the following is an accepted power source for a legally required standby system?

A generator set
A garden hose
A telephone line
No source is ever acceptable

NEC Reference: NEC 701.12

Question 13: Fixed electric heating equipment needs a disconnect that is within sight, or if not, is:

Lockable in the open position
Never required
Hidden inside the heater
Located in another building

NEC Reference: NEC 424.19

Question 14: Embedded floor heating cable should not be installed under permanently fixed cabinets because:

Heat loss is blocked, risking overheating
It looks bad
It costs more money
There is no reason

NEC Reference: NEC 424.44(E)

Question 15: Receptacle outlets should not be mounted above an electric baseboard heater if the maker's instructions:

Prohibit that location
Are always ignored
Do not matter
Only cover paint color

NEC Reference: NEC 424.9

Question 16: A storage-type water heater's overcurrent protection should not go over what percent of the branch-circuit rating?

100 %
125 %
150 %
200 %

NEC Reference: NEC 422.11(E)

Question 17: A single electric range rated 12 kW or less generally has a branch-circuit demand load of:

6 kW
8 kW
10 kW
12 kW

NEC Reference: NEC Table 220.55

Question 18: Along a kitchen countertop, receptacles must be placed so no point is more than how far from an outlet?

12 inches
24 inches
48 inches
6 feet

NEC Reference: NEC 210.52(C)(1)

Question 19: The small appliance circuits must only supply receptacles in the kitchen and dining areas, not:

Lighting outlets in another room
More kitchen receptacles
The refrigerator
The dining room table area

NEC Reference: NEC 210.52(B)(1)

Question 20: Central heating equipment (other than fixed electric heat) must be supplied by:

An individual branch circuit
The kitchen circuit
Any lighting circuit
A shared water heater circuit

NEC Reference: NEC 210.11(C)(4)

Question 21: A multiwire branch circuit feeding more than one device on the same yoke needs a way to:

Disconnect all ungrounded conductors together
Disconnect only the neutral
Nothing extra is needed
Disconnect one wire at a time only

NEC Reference: NEC 210.4(B)