Journeyman Electricianâs Exam Journeyman Electrician's 3 â Questions and Answers
Question 1: What is the minimum size copper equipment grounding conductor required for a circuit protected by a 100-ampere overcurrent device?
- 8 AWG (Correct answer)
- 6 AWG
- 4 AWG
- 2 AWG
Correct answer: 8 AWG
Per NEC Table 250.122, an 8 AWG copper EGC is required for circuits protected by overcurrent devices up to 100 amperes.
Question 2: A single 120-volt, 20-ampere kitchen small appliance circuit can serve a maximum of how many square feet of counter space?
- There is no square footage limit â two circuits are required regardless (Correct answer)
- 12 square feet
- 25 square feet
- 50 square feet
Correct answer: There is no square footage limit â two circuits are required regardless
NEC 210.11(C)(1) requires at least two small-appliance branch circuits for kitchen countertop receptacles, regardless of counter area.
Question 3: What is the maximum voltage drop recommended by the NEC for a branch circuit?
- 2%
- 3% (Correct answer)
- 5%
- 10%
Correct answer: 3%
NEC 210.19(A) informational note recommends that branch circuit voltage drop not exceed 3% for efficiency and performance.
Question 4: Which of the following is the correct formula to calculate the resistance of a conductor?
- R = V Ă I
- R = P / I²
- R = V / I (Correct answer)
- R = I Ă P
Correct answer: R = V / I
Ohm's Law states that resistance equals voltage divided by current (R = V/I), the fundamental relationship in electrical circuits.
Question 5: When sizing conductors for a continuous load, the conductor must be rated for at least what percentage of the continuous load?
- 100%
- 110%
- 125% (Correct answer)
- 150%
Correct answer: 125%
NEC 210.19(A)(1) and 215.2(A)(1) require conductors supplying continuous loads to be sized at 125% of the continuous load current.
Question 6: What type of overcurrent protection is required for a motor with a full-load current of 28 amperes using an inverse time breaker?
- 28 amps
- 35 amps (Correct answer)
- 40 amps
- 50 amps
Correct answer: 35 amps
NEC 430.52 and Table 430.52 allow an inverse time breaker at 250% of FLA for most AC motors; 28 Ă 2.5 = 70A, but the next standard size not exceeding is selected; however basic sizing is 125% for conductors, while breaker for motor is typically 250% FLA, next standard size = 70A.
Question 7: In a panelboard, what is the minimum clearance required between the top of the panel and the ceiling in a dedicated electrical space?
- 3 feet
- 6 feet
- The full height to the structural ceiling, minimum 6 feet (Correct answer)
- No minimum required
Correct answer: The full height to the structural ceiling, minimum 6 feet
NEC 110.26(E)(1) requires dedicated electrical equipment space extending from the floor to a height of 6 feet or the structural ceiling, whichever is lower.
Journeyman Electricianâs Exam Journeyman Electrician's 3
What is the minimum size copper equipment grounding conductor required for a circuit protected by a 100-ampere overcurrent device?