MASTER ELECTRICAL EXAM STUDY GUIDE 2026 –
COMPLETE CONCEPT REVIEW & PRACTICE MATERIALS
(LATEST EDITION)
Category 1: Theory and Calculations (Ohm's Law, Power, Efficiency)
1. In a purely resistive AC circuit, the voltage and current are:
A. In phase
B. Voltage leads current by 90°
C. Current leads voltage by 90°
D. 180° out of phase
Answer: A ✓
2. The total resistance of three 12-ohm resistors in parallel is:
A. 4 ohms
B. 36 ohms
C. 0.333 ohms
D. 0.25 ohms
Answer: A ✓
3. A 240V heater draws 20A. The power consumed is:
A. 4800W
B. 12W
C. 260W
D. 480W
Answer: A ✓
4. The primary purpose of power factor correction is to:
A. Reduce true power
B. Reduce reactive power
C. Increase circuit resistance
D. Decrease system voltage
Answer: B ✓
5. A 1-hp, 240V single-phase motor with an 85% efficiency and a 0.8 lagging power factor
will have a full-load current of approximately:
A. 4.6A
, B. 5.4A
C. 6.8A
D. 8.2A
Answer: B ✓ (Formula: I = (746W/hp) / (V * Eff * PF) = 746 / (240 * 0.85 * 0.8) ≈ 5.47A)
Category 2: NEC Code – General Requirements & Definitions
6. As defined in the NEC, the "effective ground-fault current path" is intended to:
A. Carry leaking current safely to ground
B. Facilitate the operation of the overcurrent device
C. Provide a low-impedance path for fault current
D. All of the above ✓
Answer: D ✓
7. Which of the following is considered a "continuous load"?
A. A store's lighting circuit expected to operate for 3 hours
B. A motor expected to run in 15-minute intervals
C. A sign circuit operating over 3 hours ✓
D. A residential kitchen countertop receptacle
Answer: C ✓
8. The minimum headroom for working spaces around service equipment is:
A. 6 feet
B. 6.5 feet
C. 7 feet
D. 8 feet
Answer: B ✓ (NEC 110.26(A)(2))
9. The minimum working space depth in front of a 480V panel with exposed live parts on
one side and a grounded wall on the other is:
A. 3 ft.
B. 3.5 ft.
C. 4 ft.
D. 4.5 ft.
Answer: C ✓ (Table 110.26(A)(1), Condition 2)
10. Equipment that is "listed" is:
A. Approved by the local inspector
B. Evaluated by a Nationally Recognized Testing Laboratory (NRTL) ✓
, C. Identified by the manufacturer as safe
D. Required to be used in all installations
Answer: B ✓
Category 3: NEC Code – Wiring Methods & Materials
11. What is the maximum fill percentage for more than two current-carrying conductors in a
raceway?
A. 30%
B. 40%
C. 50%
D. 60%
Answer: B ✓ (NEC Table 1, Chapter 9)
12. The minimum burial depth for PVC-sheathed (UF) cable under a residential driveway is:
A. 12 inches
B. 18 inches
C. 24 inches
D. 6 inches
Answer: C ✓ (Table 300.5, Column 3)
13. Type MC Cable in an accessible attic may be secured at intervals not exceeding:
A. 4.5 feet
B. 6 feet
C. 12 feet
D. Every junction box
Answer: B ✓ (NEC 330.30)
14. The minimum trade size flexible metal conduit (FMC) allowed for enclosing conductors
is:
A. 1/4 inch
B. 3/8 inch
C. 1/2 inch
D. 3/4 inch
Answer: C ✓ (NEC 348.20(A))
15. Conductors for general branch circuits must be at least what size?
A. 14 AWG Copper
B. 12 AWG Aluminum
, C. 14 AWG Aluminum
D. 12 AWG Copper
Answer: A ✓ (NEC 310.3, 240.4(D) references 14 AWG min for specific circuits)
Category 4: NEC Code – Overcurrent Protection
16. The maximum standard inverse-time circuit breaker size for protecting a 14 AWG copper
conductor on a 15A branch circuit is:
A. 15A ✓
B. 20A
C. 25A
D. 30A
Answer: A ✓ (240.4(D)(3))
17. A continuous load of 28A on a 120V circuit requires an overcurrent device rated at least:
A. 30A
B. 35A
C. 40A
D. 50A
Answer: B ✓ (125% of 28A = 35A; 210.20(A))
18. Tap conductors supplying a single motor must have an ampacity of at least what
percentage of the motor's full-load current?
A. 100%
B. 125%
C. 150%
D. 200%
Answer: B ✓ (NEC 430.53(A))
19. The primary purpose of an "adjustable trip" circuit breaker is to:
A. Allow for temporary overloads
B. Match the trip characteristic to the protected conductor ✓
C. Provide ground-fault protection
D. Act as a disconnect switch
Answer: B ✓
20. Which of the following requires "instantaneous trip" circuit breakers?
A. Motor short-circuit and ground-fault protection ✓
B. Lighting panel mains
COMPLETE CONCEPT REVIEW & PRACTICE MATERIALS
(LATEST EDITION)
Category 1: Theory and Calculations (Ohm's Law, Power, Efficiency)
1. In a purely resistive AC circuit, the voltage and current are:
A. In phase
B. Voltage leads current by 90°
C. Current leads voltage by 90°
D. 180° out of phase
Answer: A ✓
2. The total resistance of three 12-ohm resistors in parallel is:
A. 4 ohms
B. 36 ohms
C. 0.333 ohms
D. 0.25 ohms
Answer: A ✓
3. A 240V heater draws 20A. The power consumed is:
A. 4800W
B. 12W
C. 260W
D. 480W
Answer: A ✓
4. The primary purpose of power factor correction is to:
A. Reduce true power
B. Reduce reactive power
C. Increase circuit resistance
D. Decrease system voltage
Answer: B ✓
5. A 1-hp, 240V single-phase motor with an 85% efficiency and a 0.8 lagging power factor
will have a full-load current of approximately:
A. 4.6A
, B. 5.4A
C. 6.8A
D. 8.2A
Answer: B ✓ (Formula: I = (746W/hp) / (V * Eff * PF) = 746 / (240 * 0.85 * 0.8) ≈ 5.47A)
Category 2: NEC Code – General Requirements & Definitions
6. As defined in the NEC, the "effective ground-fault current path" is intended to:
A. Carry leaking current safely to ground
B. Facilitate the operation of the overcurrent device
C. Provide a low-impedance path for fault current
D. All of the above ✓
Answer: D ✓
7. Which of the following is considered a "continuous load"?
A. A store's lighting circuit expected to operate for 3 hours
B. A motor expected to run in 15-minute intervals
C. A sign circuit operating over 3 hours ✓
D. A residential kitchen countertop receptacle
Answer: C ✓
8. The minimum headroom for working spaces around service equipment is:
A. 6 feet
B. 6.5 feet
C. 7 feet
D. 8 feet
Answer: B ✓ (NEC 110.26(A)(2))
9. The minimum working space depth in front of a 480V panel with exposed live parts on
one side and a grounded wall on the other is:
A. 3 ft.
B. 3.5 ft.
C. 4 ft.
D. 4.5 ft.
Answer: C ✓ (Table 110.26(A)(1), Condition 2)
10. Equipment that is "listed" is:
A. Approved by the local inspector
B. Evaluated by a Nationally Recognized Testing Laboratory (NRTL) ✓
, C. Identified by the manufacturer as safe
D. Required to be used in all installations
Answer: B ✓
Category 3: NEC Code – Wiring Methods & Materials
11. What is the maximum fill percentage for more than two current-carrying conductors in a
raceway?
A. 30%
B. 40%
C. 50%
D. 60%
Answer: B ✓ (NEC Table 1, Chapter 9)
12. The minimum burial depth for PVC-sheathed (UF) cable under a residential driveway is:
A. 12 inches
B. 18 inches
C. 24 inches
D. 6 inches
Answer: C ✓ (Table 300.5, Column 3)
13. Type MC Cable in an accessible attic may be secured at intervals not exceeding:
A. 4.5 feet
B. 6 feet
C. 12 feet
D. Every junction box
Answer: B ✓ (NEC 330.30)
14. The minimum trade size flexible metal conduit (FMC) allowed for enclosing conductors
is:
A. 1/4 inch
B. 3/8 inch
C. 1/2 inch
D. 3/4 inch
Answer: C ✓ (NEC 348.20(A))
15. Conductors for general branch circuits must be at least what size?
A. 14 AWG Copper
B. 12 AWG Aluminum
, C. 14 AWG Aluminum
D. 12 AWG Copper
Answer: A ✓ (NEC 310.3, 240.4(D) references 14 AWG min for specific circuits)
Category 4: NEC Code – Overcurrent Protection
16. The maximum standard inverse-time circuit breaker size for protecting a 14 AWG copper
conductor on a 15A branch circuit is:
A. 15A ✓
B. 20A
C. 25A
D. 30A
Answer: A ✓ (240.4(D)(3))
17. A continuous load of 28A on a 120V circuit requires an overcurrent device rated at least:
A. 30A
B. 35A
C. 40A
D. 50A
Answer: B ✓ (125% of 28A = 35A; 210.20(A))
18. Tap conductors supplying a single motor must have an ampacity of at least what
percentage of the motor's full-load current?
A. 100%
B. 125%
C. 150%
D. 200%
Answer: B ✓ (NEC 430.53(A))
19. The primary purpose of an "adjustable trip" circuit breaker is to:
A. Allow for temporary overloads
B. Match the trip characteristic to the protected conductor ✓
C. Provide ground-fault protection
D. Act as a disconnect switch
Answer: B ✓
20. Which of the following requires "instantaneous trip" circuit breakers?
A. Motor short-circuit and ground-fault protection ✓
B. Lighting panel mains
