Practice Quiz 2020 NEC

A __________ branch circuit shall be permitted to supply cooking

appliances that are fastened in place in any occupancy.

• 40 amps

• 50 amp

• 60 amp

• 40 or 50 amps

Answer explanation

210.23 (C)

An outlet box hood installed in wet locations shall be listed and shall be identified as ___________.

• " extra duty"

• "outdoor-use"

• " weather-usage"

• " for damp locations"

Answer explanation

406.9 (B) (1)

A receptacle mounted in the type of cover shown here is

required to be held rigidly against the surface by _____.

• only one screw is required

• by more than one screw

• all three screws are required

• identified boxes

Answer explanation

406.5 (C)

The dryer shown has a nameplate rating of 4.5 kW.

The demand required on the service is ______.

• 4,500 va

• 5,000 va

• 5,500 va

• 4,000 va

Answer explanation

220.54 minimum 5000 va

Non-locking 15-20 - ampere 125-250v receptacles installed in __________ shall be listed as tamper-resistant.

• dwelling units

• child care facilities

• assisted living facilities

• all of these

Answer explanation

406.12 1. 3. 8.

A school building has a total connected load of 450 kVA and a square footage of 15,000.

Using the optional method what is the service demand?

• 450,000 va

• 18,250 va

• 273,750 va

• 30,000 va

Answer explanation

220.86

First 3 va @ 100 % = 3 va

next 17 va @ 75 % = 12.75 va

remainder 10 va @ 25 % = 2..5 va

30 va sq. ft. = 18.25 sq. ft.

18.25 x 15000 = 273,750 va

Color coding shall be permitted to identify raceways , cable trays and junction

boxes where colored light blue and contain only __________ wiring .

• both AC and DC

• DC

• circuits associated with

  water equipment

• intrinsically safe

Answer explanation

504.80 (C)

Given: The resistors in the diagram are rated the following values

R ₁ = 6 Ω R₂ = 4 Ω R₃ = 2 Ω

What is the total resistance in this circuit?

• 4 Ω

• 2.4 Ω

• 12 Ω

• 24 Ω

Answer explanation

Series circuits Resistance adds

6 + 4 + 2 = 12 ohms

A branch circuit rated 20A is fed with a No. 12 conductor.

The maximum load permitted on this receptacle is ____.

• 12A

• 15A

• 16A

• 20A

Answer explanation

Table 210.24

The voltage drop permitted on a sensitive electronic equipment circuit is limited to _________ %.

• 3

• 5

• 1.5

• .5

Answer explanation

647.4 (D)