NICET Electrical Power Testing – Level IV
Practice Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download PDF
1. Which instrument is commonly used to measure high-voltage
insulation resistance?
a) Voltmeter
b) Ammeter
c) Megohmmeter
d) Oscilloscope
Megohmmeters are designed to measure insulation resistance at
high voltages to detect deterioration.
2. When performing a transformer turns ratio test, what is the
primary purpose?
a) Measure insulation resistance
b) Verify the ratio of primary to secondary windings
c) Test the breaker operation
d) Determine voltage drop
Turns ratio testing ensures the transformer is correctly wound and
can deliver the correct output voltage.
3. What is the primary hazard when performing high-voltage
testing?
a) Low voltage shock
b) Electric shock or arc flash
c) Magnetic field exposure
, d) Noise exposure
High-voltage testing poses serious risk of electric shock and arc
flash; proper PPE is critical.
4. A hipot test is performed to:
a) Measure current flow under normal operation
b) Measure voltage drop
c) Verify insulation can withstand high voltage
d) Determine power factor
Hipot testing applies high voltage to ensure insulation can safely
operate above rated voltage.
5. Which type of relay is typically tested using a secondary injection
method?
a) Thermal overload relay
b) Electromechanical protective relay
c) Differential relay
d) Solid-state relay
Secondary injection tests energize the relay coil without applying
full system voltage.
6. Which factor most affects insulation resistance readings?
a) Conductor material
b) Temperature and humidity
c) Wire color
d) System frequency
Moisture and temperature influence the resistance of insulation
significantly.
7. When testing a circuit breaker, which of the following is critical to
verify?
a) Conductor length
b) Grounding resistance
, c) Trip time and current rating
d) Voltage drop
Breakers must operate within specified trip times to protect
equipment and personnel.
8. A partial discharge test is used primarily on:
a) Low-voltage wiring
b) High-voltage cables and transformers
c) Circuit breakers
d) Protective relays
Partial discharge testing detects insulation defects before
catastrophic failure.
9. Which instrument is used to detect magnetic flux leakage in
transformers?
a) Megohmmeter
b) Flux meter
c) Voltmeter
d) Oscilloscope
Flux meters measure magnetic flux and detect anomalies in
transformer cores.
10. During a DC insulation resistance test, the reading suddenly
drops to near zero. This may indicate:
a) Proper insulation
b) A short or insulation failure
c) Low system voltage
d) Correct grounding
A sudden drop in insulation resistance indicates breakdown or
short circuits.
11. When performing a transformer power factor test, the
primary concern is:
Practice Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download PDF
1. Which instrument is commonly used to measure high-voltage
insulation resistance?
a) Voltmeter
b) Ammeter
c) Megohmmeter
d) Oscilloscope
Megohmmeters are designed to measure insulation resistance at
high voltages to detect deterioration.
2. When performing a transformer turns ratio test, what is the
primary purpose?
a) Measure insulation resistance
b) Verify the ratio of primary to secondary windings
c) Test the breaker operation
d) Determine voltage drop
Turns ratio testing ensures the transformer is correctly wound and
can deliver the correct output voltage.
3. What is the primary hazard when performing high-voltage
testing?
a) Low voltage shock
b) Electric shock or arc flash
c) Magnetic field exposure
, d) Noise exposure
High-voltage testing poses serious risk of electric shock and arc
flash; proper PPE is critical.
4. A hipot test is performed to:
a) Measure current flow under normal operation
b) Measure voltage drop
c) Verify insulation can withstand high voltage
d) Determine power factor
Hipot testing applies high voltage to ensure insulation can safely
operate above rated voltage.
5. Which type of relay is typically tested using a secondary injection
method?
a) Thermal overload relay
b) Electromechanical protective relay
c) Differential relay
d) Solid-state relay
Secondary injection tests energize the relay coil without applying
full system voltage.
6. Which factor most affects insulation resistance readings?
a) Conductor material
b) Temperature and humidity
c) Wire color
d) System frequency
Moisture and temperature influence the resistance of insulation
significantly.
7. When testing a circuit breaker, which of the following is critical to
verify?
a) Conductor length
b) Grounding resistance
, c) Trip time and current rating
d) Voltage drop
Breakers must operate within specified trip times to protect
equipment and personnel.
8. A partial discharge test is used primarily on:
a) Low-voltage wiring
b) High-voltage cables and transformers
c) Circuit breakers
d) Protective relays
Partial discharge testing detects insulation defects before
catastrophic failure.
9. Which instrument is used to detect magnetic flux leakage in
transformers?
a) Megohmmeter
b) Flux meter
c) Voltmeter
d) Oscilloscope
Flux meters measure magnetic flux and detect anomalies in
transformer cores.
10. During a DC insulation resistance test, the reading suddenly
drops to near zero. This may indicate:
a) Proper insulation
b) A short or insulation failure
c) Low system voltage
d) Correct grounding
A sudden drop in insulation resistance indicates breakdown or
short circuits.
11. When performing a transformer power factor test, the
primary concern is:
