NEC Code Questions Practice Test-4

Question 1: What is ampacity of 1/0 THWN conductor in a dry location at an ambient temperature of 104⁰ F if the raceway contains four 1/0 THWN conductors?

• 132
• 124
• 165
• 170

NEC Reference: NEC 310.15(B)(16)

Question 2: What size conductor are required for a single family dwelling unit with a calculated load of 220 Amperes and the maximum unbalanced neutral load is 110 amperes?

• 1/0 AWG and 4 AWG
• 3/0 AWG and 3 AWG
• 3/0 AWG and 2 AWG
• 2/0 AWG and 2 AWG

NEC Reference: NEC 310.15(B)(7)

Question 3: What is the minimum size of copper conductor used for surge protective devices?

• 14 AWG
• 12 AWG
• 10 AWG
• 8 AWG

NEC Reference: NEC 285.26

Question 4: If storage batteries are used as emergency power systems. what is the minimum time that they should supply emergency loads?

• 1 1/2 hours
• 1 hour
• 1/2 hour
• 2 hours

NEC Reference: NEC 700.12

Question 5: In a wet location, the enclosure shall be mounted that there is at least ................... airspace between enclosure and the wall.

• 1/4 inch
• 1/2 inch
• 3/4 inch
• 1 inch

NEC Reference: NEC 312.2

Question 6: The low voltage lighting system transformer has a power rating of 300 watts at 15 volts. How many 25 watts lams can be connected in the lighting system?

• 12
• 10
• 15
• 11

Question 7: The building entry points of underground ducts or conduits must be sealed.

• False
• True

NEC Reference: NEC 230.8

Question 8: What is the demand factor in percentage for a non-dwelling unit with a receptacle load of 15 kVA?

• 50 %
• 75 %
• 90 %
• 82 %

NEC Reference: NEC 220.44

Question 9: The computed branch circuit load should not be less than which of the following percentage of continuous load in the circuit?

• 100 %
• 125 %
• 115 %
• 150 %

Question 10: Receptacles installed on 20 ampere branch circuit shall not be of grounding type.

• True
• False