NICET Electrical Power Testing – Level II
Practice Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
Instant Download PDF
1. What is the primary purpose of insulation resistance testing in
electrical systems?
A. To measure voltage drop
B. To verify conductor continuity
C. To detect insulation deterioration
D. To determine current load
Insulation resistance testing evaluates the condition of insulation
and identifies potential breakdowns before failure occurs.
2. Which instrument is typically used to perform a ground resistance
test?
A. Voltmeter
B. Ammeter
C. Megohmmeter
D. Ohmmeter
Megohmmeters measure high resistance levels, which is essential
for detecting insulation issues and ground resistance.
3. What does a high insulation resistance reading generally indicate?
A. Moisture presence
B. Good insulation condition
C. Short circuit
, D. Open circuit
A high reading suggests that the insulation is effective and has not
degraded.
4. What frequency is commonly used for dielectric testing of
electrical equipment?
A. 50 Hz
B. 60 Hz
C. 60 Hz or manufacturer-specified DC voltage
D. 400 Hz
Dielectric testing can be AC or DC depending on the equipment
and standards.
5. A step voltage test is primarily used to detect:
A. Overcurrent conditions
B. Weak spots in insulation
C. Ground faults
D. Voltage fluctuations
Step voltage tests gradually increase voltage to identify insulation
weaknesses without causing sudden failure.
6. What is the acceptable insulation resistance value for a motor
rated at 480V after 1 minute of testing?
A. 0.5 MΩ
B. 1 MΩ
C. 1 MΩ per 1000V of operating voltage
D. 10 MΩ
Standards typically require a minimum of 1 MΩ per 1000V of
operating voltage for acceptable insulation.
7. Which test method is used to determine the condition of a circuit
breaker’s trip unit?
A. Megger test
, B. Ground test
C. Secondary injection test
D. IR test
Secondary injection tests simulate fault currents to evaluate the
trip unit without high-voltage exposure.
8. During a transformer turns ratio test, an unexpected reading may
indicate:
A. Normal operation
B. Shorted or open winding
C. Low insulation resistance
D. Incorrect grounding
A deviation from expected ratio values suggests winding damage
or internal faults.
9. What is the purpose of power factor testing on electrical
equipment?
A. Measure current load
B. Evaluate insulation quality
C. Measure voltage drop
D. Test for grounding
Power factor testing detects insulation deterioration by measuring
reactive versus resistive components of current.
10. Which type of relay test involves applying actual current
through the relay?
A. Insulation resistance test
B. Dielectric test
C. Primary injection test
D. Turns ratio test
Primary injection tests use real current to verify relay operation
under normal and fault conditions.
Practice Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
Instant Download PDF
1. What is the primary purpose of insulation resistance testing in
electrical systems?
A. To measure voltage drop
B. To verify conductor continuity
C. To detect insulation deterioration
D. To determine current load
Insulation resistance testing evaluates the condition of insulation
and identifies potential breakdowns before failure occurs.
2. Which instrument is typically used to perform a ground resistance
test?
A. Voltmeter
B. Ammeter
C. Megohmmeter
D. Ohmmeter
Megohmmeters measure high resistance levels, which is essential
for detecting insulation issues and ground resistance.
3. What does a high insulation resistance reading generally indicate?
A. Moisture presence
B. Good insulation condition
C. Short circuit
, D. Open circuit
A high reading suggests that the insulation is effective and has not
degraded.
4. What frequency is commonly used for dielectric testing of
electrical equipment?
A. 50 Hz
B. 60 Hz
C. 60 Hz or manufacturer-specified DC voltage
D. 400 Hz
Dielectric testing can be AC or DC depending on the equipment
and standards.
5. A step voltage test is primarily used to detect:
A. Overcurrent conditions
B. Weak spots in insulation
C. Ground faults
D. Voltage fluctuations
Step voltage tests gradually increase voltage to identify insulation
weaknesses without causing sudden failure.
6. What is the acceptable insulation resistance value for a motor
rated at 480V after 1 minute of testing?
A. 0.5 MΩ
B. 1 MΩ
C. 1 MΩ per 1000V of operating voltage
D. 10 MΩ
Standards typically require a minimum of 1 MΩ per 1000V of
operating voltage for acceptable insulation.
7. Which test method is used to determine the condition of a circuit
breaker’s trip unit?
A. Megger test
, B. Ground test
C. Secondary injection test
D. IR test
Secondary injection tests simulate fault currents to evaluate the
trip unit without high-voltage exposure.
8. During a transformer turns ratio test, an unexpected reading may
indicate:
A. Normal operation
B. Shorted or open winding
C. Low insulation resistance
D. Incorrect grounding
A deviation from expected ratio values suggests winding damage
or internal faults.
9. What is the purpose of power factor testing on electrical
equipment?
A. Measure current load
B. Evaluate insulation quality
C. Measure voltage drop
D. Test for grounding
Power factor testing detects insulation deterioration by measuring
reactive versus resistive components of current.
10. Which type of relay test involves applying actual current
through the relay?
A. Insulation resistance test
B. Dielectric test
C. Primary injection test
D. Turns ratio test
Primary injection tests use real current to verify relay operation
under normal and fault conditions.
