Licensed Electrical Contractor Code, Theory, and Calculations 3

Question 1

What NEC section governs the installation of conductors in raceways, and what is the maximum fill percentage for a single conductor in a conduit?

Accepted Answer

NEC 300.17 — 53%

Answer

NEC 358.22 — 53%

Answer

NEC 344.22 — 31%

Answer

NEC 310.15 — 40%

Question 2

What is the reactance of a 60 Hz circuit with an inductance of 0.5 H?

Accepted Answer

188.5 Ω

Answer

94.2 Ω

Answer

376.9 Ω

Answer

30 Ω

Question 3

Under NEC 210.8(A), GFCI protection is required for all 125 V, 15 A and 20 A receptacles in which residential location?

Accepted Answer

All outdoor locations

Answer

Living room only

Answer

Bedrooms only

Answer

Attic storage areas only

Question 4

A 480 V, 3-phase, 4-wire wye system has a line-to-neutral voltage of approximately:

Accepted Answer

277 V

Answer

240 V

Answer

208 V

Answer

347 V

Question 5

Per NEC 250.122, the minimum size equipment grounding conductor (EGC) for a circuit protected by a 200 A overcurrent device is:

Accepted Answer

6 AWG copper

Answer

4 AWG copper

Answer

8 AWG copper

Answer

2 AWG copper

Question 6

In a capacitive AC circuit, the current:

Accepted Answer

Leads the voltage by 90°

Answer

Lags the voltage by 90°

Answer

Is in phase with voltage

Answer

Leads the voltage by 45°

Question 7

NEC 408.36 requires panelboards supplied by a 4-wire delta system to be labeled to indicate the:

Accepted Answer

High-leg (wild leg) conductor and its voltage to ground

Answer

Total panel ampacity rating

Answer

Number of branch circuits permitted

Answer

Grounding conductor size