Question 1: What is the required size of a neutral conductor for a dwelling unit with a calculated load of 220 A. The unbalanced load is 120 A and service disconnect rating is 250A.
- 1 AWG
- 2 AWG
- 3 AWG
- 4 AWG
NEC Reference: NEC 310.15(B)(16)
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NEC 2023
NEC Code Questions Practice Test-10
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TimeNEC Code Questions Practice Test-10 — Question List
Question 2: If a service is fed by three parallel sets of 400 kcmil conductors, what is the required conductor size for GEC?
- 3/0 AWG
- 2/0 AWG
- 2 AWG
- 4 AWG
NEC Reference: NEC 250.166
Question 3: A 400 breaker protects a set of 450 kcmil feeder conductors. A feeder fed from 450 kcmil feeder that supply disconnects with 25 A over current device. What is the minimum size conductor for these tap?
- 8 AWG
- 6 AWG
- 4 AWG
- 16 AWG
NEC Reference: NEC 310.15(B)(16)
Question 4: What size service entrance conductors are required for 250 A continuous three phase load if the terminals are at ambient temperature of 70 C?
- 3/0 AWG
- 250 kcmil
- 400 kcmil
- 2/0 AWG
NEC Reference: NEC 312.5
Question 5: Under which of the following condition the on-site generator is not considered as separately derived system?
- When the generator does not have neutral conductor
- When the generator is placed near the feeder service conductor panel board
- Generator having transfer witch that switches the neutral conductor also
- When generator neutral conductor is solidly interconnected service supply system neutral conductor
NEC Reference: NEC 250.30
Question 6: When the circuits are protected by a over current device rating of 1000 A, what size bonding jumper is required for each metal raceway?
- 1/0 AWG
- 2/0 AWG
- 3/0 AWG
- 4 AWG
NEC Reference: NEC 250.122
Question 7: When five conductors each with an ampacity of 25 A bundled through NM cable, what is the adjusted ampacity of each cable.
- 25 amperes
- 20 amperes
- 30 amperes
- 22.5 amperes
NEC Reference: NEC 310.15(B)(3)(a)
Question 8: A 40 KVA , 480 V three phase transformer has a primary over current protection device is rated at 75 A. What is the size of primary conductor that can be used?
- 2 AWG
- 4 AWG
- 3 AWG
- 1 AWG
NEC Reference: NEC 310.15(B)(16)
Question 9: How many number of 500 kcmil THWN conductors that can be installed in a 4 in. * 4 in. wireway?
- 4 conductors
- 5 conductors
- 6 conductors
- 7 conductors
NEC Reference: NEC 376.22(A)
Question 10: What size service entrance conductors are required for 250 A continuous three phase load if the terminals are at ambient temperature of 70 C?
- 3/0 AWG
- 250 kcmil
- 400 kcmil
- 2/0 AWG
NEC Reference: NEC 312.5
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