ELECTRICAL POWER DISTRIBUTION QUALIFICATION
EXAM LATEST 2026 VERSION WITH 100 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW VERSION!!
1. What is the primary purpose of a circuit breaker in a power distribution
system?
A. Increase voltage
B. Store electrical energy
C. Protect circuits from overcurrent
D. Convert AC to DC
C. Protect circuits from overcurrent Circuit breakers automatically
disconnect power when excessive current flows, preventing damage to
equipment and fire hazards.
2. Which type of transformer is commonly used to step down voltage for
residential distribution?
A. Isolation transformer
B. Distribution transformer
C. Power transformer
D. Autotransformer
B. Distribution transformer Distribution transformers reduce high
transmission voltages to levels suitable for residential or commercial use.
3. In a three-phase system, what is the phase voltage if the line voltage is 400
V?
A. 230 V
B. 346 V
C. 400 V
D. 690 V
, A. 230 V Phase voltage in a three-phase system is calculated as V_phase =
V_line / √3; 400 / √3 ≈ 230 V.
4. What does the color coding of electrical wires indicate?
A. Electrical resistance
B. Voltage rating
C. Conductor function
D. Material type
C. Conductor function Color codes distinguish live, neutral, and grounding
conductors to ensure safe and correct wiring.
5. Which protective device responds faster to short circuits?
A. Fuse
B. Grounding rod
C. Contactor
D. Voltmeter
A. Fuse Fuses melt quickly under high current conditions, providing rapid
disconnection during short circuits.
6. What is the primary function of a grounding system in power distribution?
A. Increase voltage
B. Protect equipment and personnel from faults
C. Reduce current
D. Store energy
B. Protect equipment and personnel from faults Grounding provides a low-
resistance path for fault currents, minimizing risk of shock or fire.
7. Which system is typically used for high-voltage long-distance transmission?
A. DC transmission
B. AC transmission
C. Wireless transmission
D. Photovoltaic system
B. AC transmission Alternating current is preferred for high-voltage
transmission due to easy voltage transformation and efficiency.
, 8. What is the main disadvantage of a radial distribution system?
A. Complex design
B. High reliability
C. Single point of failure
D. Low cost
C. Single point of failure Radial systems are simple and cheap but a fault in
the main line interrupts service to all downstream loads.
9. Which instrument is used to measure electrical current in a circuit?
A. Voltmeter
B. Ammeter
C. Ohmmeter
D. Wattmeter
B. Ammeter Ammeters are connected in series with the circuit to measure
current flow.
10.Which type of relay is commonly used for overcurrent protection?
A. Thermal relay
B. Electromagnetic relay
C. Differential relay
D. Time-delay fuse
B. Electromagnetic relay Electromagnetic relays detect excessive current
and initiate disconnection to protect circuits.
11.In a three-phase, four-wire system, which conductor carries the neutral
current?
A. Line A
B. Line B
C. Line C
D. Neutral
D. Neutral The neutral conductor carries the imbalance current in a three-
phase, four-wire system.
12.What is the purpose of a lightning arrester in power distribution?
A. Reduce load demand
EXAM LATEST 2026 VERSION WITH 100 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW VERSION!!
1. What is the primary purpose of a circuit breaker in a power distribution
system?
A. Increase voltage
B. Store electrical energy
C. Protect circuits from overcurrent
D. Convert AC to DC
C. Protect circuits from overcurrent Circuit breakers automatically
disconnect power when excessive current flows, preventing damage to
equipment and fire hazards.
2. Which type of transformer is commonly used to step down voltage for
residential distribution?
A. Isolation transformer
B. Distribution transformer
C. Power transformer
D. Autotransformer
B. Distribution transformer Distribution transformers reduce high
transmission voltages to levels suitable for residential or commercial use.
3. In a three-phase system, what is the phase voltage if the line voltage is 400
V?
A. 230 V
B. 346 V
C. 400 V
D. 690 V
, A. 230 V Phase voltage in a three-phase system is calculated as V_phase =
V_line / √3; 400 / √3 ≈ 230 V.
4. What does the color coding of electrical wires indicate?
A. Electrical resistance
B. Voltage rating
C. Conductor function
D. Material type
C. Conductor function Color codes distinguish live, neutral, and grounding
conductors to ensure safe and correct wiring.
5. Which protective device responds faster to short circuits?
A. Fuse
B. Grounding rod
C. Contactor
D. Voltmeter
A. Fuse Fuses melt quickly under high current conditions, providing rapid
disconnection during short circuits.
6. What is the primary function of a grounding system in power distribution?
A. Increase voltage
B. Protect equipment and personnel from faults
C. Reduce current
D. Store energy
B. Protect equipment and personnel from faults Grounding provides a low-
resistance path for fault currents, minimizing risk of shock or fire.
7. Which system is typically used for high-voltage long-distance transmission?
A. DC transmission
B. AC transmission
C. Wireless transmission
D. Photovoltaic system
B. AC transmission Alternating current is preferred for high-voltage
transmission due to easy voltage transformation and efficiency.
, 8. What is the main disadvantage of a radial distribution system?
A. Complex design
B. High reliability
C. Single point of failure
D. Low cost
C. Single point of failure Radial systems are simple and cheap but a fault in
the main line interrupts service to all downstream loads.
9. Which instrument is used to measure electrical current in a circuit?
A. Voltmeter
B. Ammeter
C. Ohmmeter
D. Wattmeter
B. Ammeter Ammeters are connected in series with the circuit to measure
current flow.
10.Which type of relay is commonly used for overcurrent protection?
A. Thermal relay
B. Electromagnetic relay
C. Differential relay
D. Time-delay fuse
B. Electromagnetic relay Electromagnetic relays detect excessive current
and initiate disconnection to protect circuits.
11.In a three-phase, four-wire system, which conductor carries the neutral
current?
A. Line A
B. Line B
C. Line C
D. Neutral
D. Neutral The neutral conductor carries the imbalance current in a three-
phase, four-wire system.
12.What is the purpose of a lightning arrester in power distribution?
A. Reduce load demand
