NEC ELECTRIC TEST

Question 1

The voltage waveform will lag behind the current waveform in a circuit supplying electricity to capacitive loads:

Accepted Answer

True

Answer

False

Question 2

Which of the following machines is the most efficient?

Accepted Answer

Electrical Transformer

Answer

DC Motor

Answer

Synchronous machine

Answer

Induction motor

Question 3

During no-load operation, an induction motor's power factor will be in the range:

Accepted Answer

0.2

Answer

0.9

Answer

0.7

Answer

0.5

Question 4

Conductors with  _____ marked on the insulation are not allowed to be used in wet locations.

Accepted Answer

THHN

Answer

THW

Answer

THWN

Answer

THHW

Question 5

Given: The local utility company provides a 120/240 volt, single-phase electrical system to a one-family dwelling unit with a demand load of
 200 amperes. What is the MINIMUM size of aluminum THW conductors required for this residence's service-entrance conductors?

Accepted Answer

4/0 AWG

Answer

3/0 AWG

Answer

2/0 AWG

Answer

1/0 AWG

Question 6

The full-load current rating, in amperes, of a 150 kVA single-phase transformer with a secondary voltage of 120/240 installed in a multi-family dwelling is  _____.

Accepted Answer

625 amperes

Answer

526 amperes

Answer

1250 amperes

Answer

265 amperes

Question 7

Which of the circuit breakers listed below does not have a standard ampere rating?

Accepted Answer

75 amperes

Answer

225 amperes

Answer

110 amperes

Answer

90 amperes

Question 8

The MINIMUM length of the free conductor must be left at each junction box for splicing conductors or connecting to luminaires or devices is.

Accepted Answer

6 inches

Answer

8 inches

Answer

4 inches

Answer

10 inches

Question 9

Overhead service-drop conductors must not be smaller than  _____ in general.

Accepted Answer

8 AWG copper

Answer

6 AWG copper

Answer

4 AWG copper

Answer

2 AWG copper

Question 10

The NEC specifies that a galvanized eye-bolt be installed NOT less than  _____ above finished grade when used as a point of attachment for electrical service.

Accepted Answer

10 ft.

Answer

15 ft.

Answer

12 ft.

Answer

8 ft.