Electrical Administrator Licensing Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. In a three-phase, four-wire 415/240 V system supplying a commercial
building, the phase currents are 90 A, 110 A, and 100 A respectively.
Which statement best describes the current in the neutral conductor?
A. The neutral current is always equal to the highest phase current.
B. The neutral current is zero because the system is three-phase.
C. The neutral current is the arithmetic sum of all phase currents.
D. The neutral current depends on the vector imbalance of the phase
currents.
Rationale: In a three-phase four-wire system, the neutral current is the
phasor (vector) sum of the phase currents. If loads are balanced, the
neutral current is zero; however, any imbalance results in current flowing
in the neutral conductor.
2. Which protective device is primarily intended to protect persons
against electric shock caused by earth leakage currents?
A. Fuse
B. MCB
C. RCD
D. Isolator
,Rationale: An RCD continuously compares outgoing and returning currents
and trips when a difference caused by leakage to earth exceeds the set
threshold, thereby reducing the risk of fatal electric shock.
3. The main purpose of grounding an electrical installation is to:
A. Increase system voltage.
B. Improve power factor.
C. Provide a low-impedance path for fault current.
D. Reduce conductor resistance.
Rationale: Grounding provides an intentional low-resistance path for fault
current, ensuring protective devices operate quickly and exposed
conductive parts do not remain energized.
4. Which instrument is specifically used to measure insulation resistance
in electrical equipment and cables?
A. Clamp meter
B. Wattmeter
C. Earth tester
D. Megger insulation tester
Rationale: A Megger applies a high DC test voltage to determine insulation
resistance, making it suitable for evaluating cable and equipment
insulation integrity.
5. A transformer operates on the principle of:
A. Electrostatic induction.
B. Magnetic attraction.
C. Self-induction only.
D. Mutual electromagnetic induction.
Rationale: A transformer transfers energy between windings through
changing magnetic flux, which induces voltage in the secondary winding
according to the principle of mutual induction.
, 6. A 10 Ω resistor connected across a 240 V supply will draw
approximately:
A. 12 A
B. 20 A
C. 24 A
D. 30 A
Rationale: Using Ohm's law, current equals voltage divided by resistance.
Therefore, I = 240 ÷ 10 = 24 A.
7. Which wiring method provides the greatest mechanical protection for
conductors in an industrial environment?
A. PVC twin-and-earth cable clipped directly.
B. Flexible cord.
C. Surface casing and capping.
D. Rigid metallic conduit.
Rationale: Rigid metallic conduit provides substantial mechanical
protection against impact, abrasion, and environmental hazards
commonly encountered in industrial installations.
8. A conductor carrying current above its rated ampacity may result in:
A. Improved efficiency.
B. Reduced voltage drop only.
C. Overheating and insulation failure.
D. Increased insulation resistance.
Rationale: Excess current causes excessive heat generation due to I²R
losses, which can damage insulation and create fire hazards.
9. In a star-connected three-phase system, the relationship between line
voltage (VL) and phase voltage (VP) is:
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. In a three-phase, four-wire 415/240 V system supplying a commercial
building, the phase currents are 90 A, 110 A, and 100 A respectively.
Which statement best describes the current in the neutral conductor?
A. The neutral current is always equal to the highest phase current.
B. The neutral current is zero because the system is three-phase.
C. The neutral current is the arithmetic sum of all phase currents.
D. The neutral current depends on the vector imbalance of the phase
currents.
Rationale: In a three-phase four-wire system, the neutral current is the
phasor (vector) sum of the phase currents. If loads are balanced, the
neutral current is zero; however, any imbalance results in current flowing
in the neutral conductor.
2. Which protective device is primarily intended to protect persons
against electric shock caused by earth leakage currents?
A. Fuse
B. MCB
C. RCD
D. Isolator
,Rationale: An RCD continuously compares outgoing and returning currents
and trips when a difference caused by leakage to earth exceeds the set
threshold, thereby reducing the risk of fatal electric shock.
3. The main purpose of grounding an electrical installation is to:
A. Increase system voltage.
B. Improve power factor.
C. Provide a low-impedance path for fault current.
D. Reduce conductor resistance.
Rationale: Grounding provides an intentional low-resistance path for fault
current, ensuring protective devices operate quickly and exposed
conductive parts do not remain energized.
4. Which instrument is specifically used to measure insulation resistance
in electrical equipment and cables?
A. Clamp meter
B. Wattmeter
C. Earth tester
D. Megger insulation tester
Rationale: A Megger applies a high DC test voltage to determine insulation
resistance, making it suitable for evaluating cable and equipment
insulation integrity.
5. A transformer operates on the principle of:
A. Electrostatic induction.
B. Magnetic attraction.
C. Self-induction only.
D. Mutual electromagnetic induction.
Rationale: A transformer transfers energy between windings through
changing magnetic flux, which induces voltage in the secondary winding
according to the principle of mutual induction.
, 6. A 10 Ω resistor connected across a 240 V supply will draw
approximately:
A. 12 A
B. 20 A
C. 24 A
D. 30 A
Rationale: Using Ohm's law, current equals voltage divided by resistance.
Therefore, I = 240 ÷ 10 = 24 A.
7. Which wiring method provides the greatest mechanical protection for
conductors in an industrial environment?
A. PVC twin-and-earth cable clipped directly.
B. Flexible cord.
C. Surface casing and capping.
D. Rigid metallic conduit.
Rationale: Rigid metallic conduit provides substantial mechanical
protection against impact, abrasion, and environmental hazards
commonly encountered in industrial installations.
8. A conductor carrying current above its rated ampacity may result in:
A. Improved efficiency.
B. Reduced voltage drop only.
C. Overheating and insulation failure.
D. Increased insulation resistance.
Rationale: Excess current causes excessive heat generation due to I²R
losses, which can damage insulation and create fire hazards.
9. In a star-connected three-phase system, the relationship between line
voltage (VL) and phase voltage (VP) is:
