Journeyman Electrician’s Exam Journeyman Electrician's General 5 — Questions and Answers
Question 1: What is the minimum headroom required in front of electrical equipment rated 1,200 amps or more and over 6 feet wide that contains overcurrent devices?
- 6 feet
- 6.5 feet
- 7 feet (Correct answer)
- 8 feet
Correct answer: 7 feet
NEC 110.26(E)(1)(b) requires a minimum headroom of 7 feet for service equipment, switchboards, or panelboards rated 1,200 amps or more.
Question 2: When conductors of different systems (e.g., 120V and 277V) occupy the same raceway, what is required?
- They are prohibited from sharing a raceway under any circumstances
- All conductors must be insulated for the maximum voltage present (Correct answer)
- A divider must separate the conductors
- Only THHN conductors may be used
Correct answer: All conductors must be insulated for the maximum voltage present
NEC 300.3(C)(1) permits conductors of different systems in the same raceway if all conductors are insulated for the maximum voltage of any conductor in the raceway.
Question 3: What is the maximum allowable percentage fill for three conductors in a rigid PVC conduit (Schedule 40)?
- 31% (Correct answer)
- 40%
- 53%
- 60%
Correct answer: 31%
NEC Annex C and Chapter 9, Table 1 specify a maximum conduit fill of 40% for two conductors and 31% for three or more conductors in any raceway.
Question 4: A 30-amp, 120V single-phase branch circuit requires which minimum wire gauge for copper conductors?
- 14 AWG
- 12 AWG
- 10 AWG (Correct answer)
- 8 AWG
Correct answer: 10 AWG
NEC 240.4(D) and Table 310.12 require a minimum 10 AWG copper conductor for a 30-amp branch circuit.
Question 5: Which wiring method is specifically designed for use in hazardous (classified) locations and provides both physical and gas-tight protection?
- EMT with compression fittings
- Rigid Metal Conduit (RMC) with threaded fittings (Correct answer)
- Flexible Metal Conduit (FMC)
- MC Cable (metal-clad)
Correct answer: Rigid Metal Conduit (RMC) with threaded fittings
Rigid Metal Conduit (RMC) with threaded, gas-tight fittings is the standard wiring method used in Class I, Division 1 hazardous locations to prevent ignition of flammable gases.
Question 6: What is the purpose of a 'bonding jumper' in an electrical system?
- To increase the circuit's amperage capacity
- To connect two separate grounding electrodes together
- To ensure electrical continuity and conductivity of the grounding path across metal parts (Correct answer)
- To reduce voltage drop on long circuit runs
Correct answer: To ensure electrical continuity and conductivity of the grounding path across metal parts
A bonding jumper ensures electrical continuity and adequate conductivity to conduct safely any fault current likely to be imposed on metal parts of a system.
Question 7: For a 200-amp service to a single-family dwelling, what is the minimum size copper grounding electrode conductor (GEC) required when using a concrete-encased electrode?
- 6 AWG (Correct answer)
- 4 AWG
- 2 AWG
- 1/0 AWG
Correct answer: 6 AWG
NEC 250.66(B) permits the GEC to a concrete-encased electrode to be no smaller than 4 AWG copper, but Table 250.66 sets 6 AWG as the minimum for a 200A service — and 250.66(B) allows using just 4 AWG to the Ufer regardless of service size.
Journeyman Electrician’s Exam Journeyman Electrician's General 5
What is the minimum headroom required in front of electrical equipment rated 1,200 amps or more and over 6 feet wide that contains overcurrent devices?