ELECTRICAL ENGINEERING EXAMINER EXAM QUESTION AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALE 2025/2026
Q&A/INSTANTDOWNLOAD PDF
1. Which of the following is the standard unit of electrical resistance?
A. Volt
B. Ampere
C. Ohm
D. Watt
The ohm (Ω) is the standard unit of electrical resistance, representing opposition to current flow.
2. What is the main function of a circuit breaker?
A. Increase current
B. Prevent short circuits and overloads
C. Store energy
D. Convert AC to DC
A circuit breaker automatically interrupts the flow of current to prevent damage from overloads
or short circuits.
3. According to the NEC, the minimum size for grounding electrode conductor in
a residential system is based on:
A. Service voltage
B. Size of the service-entrance conductors
C. Length of the conduit
D. Type of grounding electrode
Grounding electrode conductor size is determined by the size of service-entrance conductors per
NEC Table 250.66.
4. What color is typically used for a grounded (neutral) conductor?
A. Green
B. White or gray
C. Black
,D. Red
White or gray identifies grounded (neutral) conductors according to NEC color codes.
5. What is the purpose of a GFCI (Ground-Fault Circuit Interrupter)?
A. Protect against high voltage
B. Protect against fire
C. Protect against electric shock
D. Reduce power loss
GFCIs detect ground faults and disconnect power to prevent electric shock.
6. Which formula expresses Ohm’s Law?
A. P = V × I
B. I = V / R
C. E = I × R²
D. R = P / V
Ohm’s Law states that current (I) equals voltage (V) divided by resistance (R).
7. What is the standard voltage for residential outlets in most countries?
A. 120 V
B. 240 V
C. 12 V
D. 480 V
In North America, standard residential receptacles supply 120 volts AC.
8. Which type of conduit provides the highest level of mechanical protection?
A. EMT
B. PVC
C. RMC
D. FMC
Rigid Metal Conduit (RMC) provides the greatest mechanical protection.
, 9. A 20-ampere circuit using copper conductors requires what minimum wire
size?
A. 16 AWG
B. 14 AWG
C. 12 AWG
D. 10 AWG
Per NEC Table 310.16, a 20A circuit requires a minimum of 12 AWG copper conductors.
10. The total load on a 15A, 120V branch circuit should not exceed:
A. 1,200 watts
B. 1,440 watts
C. 1,800 watts
D. 2,000 watts
Continuous loads should not exceed 80% of circuit rating; 15A × 120V × 0.8 = 1,440W.
11. What device converts AC to DC?
A. Transformer
B. Rectifier
C. Inverter
D. Regulator
A rectifier converts alternating current (AC) to direct current (DC).
12. What is the purpose of bonding in an electrical system?
A. Increase current flow
B. Prevent corrosion
C. Ensure metallic parts are at the same potential
D. Reduce resistance
Bonding connects metallic components to ensure equal potential and prevent shock hazards.
13. The main disconnect for a service must be located:
A. Inside the transformer
B. Near the service entrance
C. In the attic
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALE 2025/2026
Q&A/INSTANTDOWNLOAD PDF
1. Which of the following is the standard unit of electrical resistance?
A. Volt
B. Ampere
C. Ohm
D. Watt
The ohm (Ω) is the standard unit of electrical resistance, representing opposition to current flow.
2. What is the main function of a circuit breaker?
A. Increase current
B. Prevent short circuits and overloads
C. Store energy
D. Convert AC to DC
A circuit breaker automatically interrupts the flow of current to prevent damage from overloads
or short circuits.
3. According to the NEC, the minimum size for grounding electrode conductor in
a residential system is based on:
A. Service voltage
B. Size of the service-entrance conductors
C. Length of the conduit
D. Type of grounding electrode
Grounding electrode conductor size is determined by the size of service-entrance conductors per
NEC Table 250.66.
4. What color is typically used for a grounded (neutral) conductor?
A. Green
B. White or gray
C. Black
,D. Red
White or gray identifies grounded (neutral) conductors according to NEC color codes.
5. What is the purpose of a GFCI (Ground-Fault Circuit Interrupter)?
A. Protect against high voltage
B. Protect against fire
C. Protect against electric shock
D. Reduce power loss
GFCIs detect ground faults and disconnect power to prevent electric shock.
6. Which formula expresses Ohm’s Law?
A. P = V × I
B. I = V / R
C. E = I × R²
D. R = P / V
Ohm’s Law states that current (I) equals voltage (V) divided by resistance (R).
7. What is the standard voltage for residential outlets in most countries?
A. 120 V
B. 240 V
C. 12 V
D. 480 V
In North America, standard residential receptacles supply 120 volts AC.
8. Which type of conduit provides the highest level of mechanical protection?
A. EMT
B. PVC
C. RMC
D. FMC
Rigid Metal Conduit (RMC) provides the greatest mechanical protection.
, 9. A 20-ampere circuit using copper conductors requires what minimum wire
size?
A. 16 AWG
B. 14 AWG
C. 12 AWG
D. 10 AWG
Per NEC Table 310.16, a 20A circuit requires a minimum of 12 AWG copper conductors.
10. The total load on a 15A, 120V branch circuit should not exceed:
A. 1,200 watts
B. 1,440 watts
C. 1,800 watts
D. 2,000 watts
Continuous loads should not exceed 80% of circuit rating; 15A × 120V × 0.8 = 1,440W.
11. What device converts AC to DC?
A. Transformer
B. Rectifier
C. Inverter
D. Regulator
A rectifier converts alternating current (AC) to direct current (DC).
12. What is the purpose of bonding in an electrical system?
A. Increase current flow
B. Prevent corrosion
C. Ensure metallic parts are at the same potential
D. Reduce resistance
Bonding connects metallic components to ensure equal potential and prevent shock hazards.
13. The main disconnect for a service must be located:
A. Inside the transformer
B. Near the service entrance
C. In the attic
