NICET Electrical Power Testing – Level III
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 power systems?
a) To measure current flow
b) To detect insulation deterioration
c) To check voltage levels
d) To calibrate meters
Insulation resistance testing identifies breakdowns or
deterioration in insulation that can lead to equipment failure or
safety hazards.
2. Which instrument is typically used for high-voltage insulation
resistance testing?
a) Voltmeter
b) Ammeter
c) Megohmmeter
d) Oscilloscope
A megohmmeter applies high DC voltage to insulation to measure
resistance, indicating its integrity.
3. During transformer turns ratio (TTR) testing, a significant
deviation from the expected ratio may indicate:
a) Overheating of windings
b) Shorted turns
, c) Low insulation resistance
d) High ambient temperature
A deviation in TTR often signals shorted turns in the transformer
winding.
4. Which type of test can identify inter-turn shorts in a transformer
winding?
a) Insulation resistance
b) Power factor
c) Sweep frequency response analysis (SFRA)
d) Ground resistance test
SFRA detects mechanical or electrical winding issues, including
inter-turn shorts, by analyzing frequency response.
5. When performing a power factor test on insulation, a high power
factor reading indicates:
a) Excellent insulation
b) Deteriorated insulation
c) Low resistance
d) Proper grounding
A high power factor indicates higher leakage current due to
insulation degradation.
6. What is the recommended safety precaution before conducting
high-voltage testing?
a) Use a multimeter
b) De-energize equipment and follow lockout/tagout procedures
c) Wear gloves only
d) Test at night
High-voltage testing requires complete isolation and safety
procedures to prevent electrical shock.
, 7. In a grounded system, a ground resistance test value above 25
ohms usually indicates:
a) Excellent grounding
b) Low soil resistivity
c) Poor grounding
d) Correct installation
High resistance in grounding can prevent proper fault current
flow, increasing risk of equipment damage.
8. The main objective of circuit breaker timing tests is to:
a) Measure insulation
b) Measure current
c) Ensure breakers operate within specified time limits
d) Calibrate meters
Timing tests verify that protective devices will respond properly to
faults.
9. When performing a low-voltage circuit breaker trip test, the trip
time is typically measured using:
a) Voltmeter
b) Ammeter
c) Stopwatch or timing device
d) Insulation tester
Accurate timing is essential to ensure proper coordination of
protective devices.
10. What is the purpose of a contact resistance test on
switchgear?
a) Measure voltage
b) Measure current
c) Identify high-resistance contacts
d) Verify insulation
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 power systems?
a) To measure current flow
b) To detect insulation deterioration
c) To check voltage levels
d) To calibrate meters
Insulation resistance testing identifies breakdowns or
deterioration in insulation that can lead to equipment failure or
safety hazards.
2. Which instrument is typically used for high-voltage insulation
resistance testing?
a) Voltmeter
b) Ammeter
c) Megohmmeter
d) Oscilloscope
A megohmmeter applies high DC voltage to insulation to measure
resistance, indicating its integrity.
3. During transformer turns ratio (TTR) testing, a significant
deviation from the expected ratio may indicate:
a) Overheating of windings
b) Shorted turns
, c) Low insulation resistance
d) High ambient temperature
A deviation in TTR often signals shorted turns in the transformer
winding.
4. Which type of test can identify inter-turn shorts in a transformer
winding?
a) Insulation resistance
b) Power factor
c) Sweep frequency response analysis (SFRA)
d) Ground resistance test
SFRA detects mechanical or electrical winding issues, including
inter-turn shorts, by analyzing frequency response.
5. When performing a power factor test on insulation, a high power
factor reading indicates:
a) Excellent insulation
b) Deteriorated insulation
c) Low resistance
d) Proper grounding
A high power factor indicates higher leakage current due to
insulation degradation.
6. What is the recommended safety precaution before conducting
high-voltage testing?
a) Use a multimeter
b) De-energize equipment and follow lockout/tagout procedures
c) Wear gloves only
d) Test at night
High-voltage testing requires complete isolation and safety
procedures to prevent electrical shock.
, 7. In a grounded system, a ground resistance test value above 25
ohms usually indicates:
a) Excellent grounding
b) Low soil resistivity
c) Poor grounding
d) Correct installation
High resistance in grounding can prevent proper fault current
flow, increasing risk of equipment damage.
8. The main objective of circuit breaker timing tests is to:
a) Measure insulation
b) Measure current
c) Ensure breakers operate within specified time limits
d) Calibrate meters
Timing tests verify that protective devices will respond properly to
faults.
9. When performing a low-voltage circuit breaker trip test, the trip
time is typically measured using:
a) Voltmeter
b) Ammeter
c) Stopwatch or timing device
d) Insulation tester
Accurate timing is essential to ensure proper coordination of
protective devices.
10. What is the purpose of a contact resistance test on
switchgear?
a) Measure voltage
b) Measure current
c) Identify high-resistance contacts
d) Verify insulation
