NETA Cheat Sheet 2026

The 30 highest-yield NETA facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. The effective (RMS) value of a sinusoidal AC voltage is approximately what fraction of the peak voltage? → 0.707 times the peak voltage
2. In a parallel RLC circuit at resonance, the circuit impedance is: → At its maximum value
3. In a series RLC circuit at resonance, which of the following is true? → Inductive and capacitive reactances are equal and cancel
4. Which UPS topology provides zero transfer time to battery during a utility power outage because the load is always powered by the inverter? → Double-conversion (online) UPS
5. The polarization index (PI) test for motor winding insulation compares the insulation resistance at: → 30 seconds and 10 minutes using the same test voltage
6. What minimum percentage of rated capacity must a battery string demonstrate during a NETA acceptance capacity test to be considered acceptable? → 80%
7. What device is used to analyze harmonics in a power system? → Power quality analyzer
8. A distance relay (ANSI Device 21) is most commonly applied for the protection of which of the following power system elements? → Transmission lines
9. According to NETA acceptance testing standards, individual float voltage measurements for battery strings should be recorded at which level? → Each individual cell
10. What causes voltage sag in a power system? → Short-duration faults or large motor starts
11. Which battery type presents the greatest risk of hydrogen gas accumulation during the charging process, requiring adequate ventilation? → Flooded vented lead-acid
12. Which equipment is essential for time current characteristic testing? → Relay test set
13. Vibration analysis on electric motors identifies which type of problem through characteristic frequency signatures? → Mechanical faults including bearing defects, unbalance, misalignment, and loose components
14. The turns ratio test on a transformer is performed to: → Verify that the actual voltage transformation ratio matches the nameplate ratio
15. Which method is commonly used to locate faults in underground cables? → Time domain reflectometry (TDR)
16. Which instrument is primarily used to measure power factor in a power system? → Power factor meter
17. The time constant of an RC circuit is defined as: → The time for the capacitor voltage to reach 63.2% of the applied voltage
18. During a circuit breaker contact resistance test, a high resistance reading typically indicates: → Worn, pitted, or corroded contacts
19. In a DC circuit, the total power dissipated can be expressed as P = V squared divided by R. This formula is derived from: → P = V*I combined with V = I*R (Ohm's law)
20. What is the minimum arc flash PPE required for Category 1? → FR shirt and pants rated 4 cal/cm²
21. What is the purpose of insulation resistance testing? → To ensure insulation is not degraded
22. For the fall-of-potential test to provide accurate results, the current and potential electrodes should be placed at minimum distances because: → The resistance spheres of influence of the electrodes must not overlap
23. When performing contact wear measurement on a vacuum circuit breaker, the technician is measuring: → The contact erosion or stroke reduction from arcing
24. Why is proper grounding tested in electrical systems? → To ensure safety and fault current dissipation
25. When performing a transformer insulation power factor test, the UST (Ungrounded Specimen Test) configuration is used to: → Eliminate the effect of surface leakage currents from the measurement
26. During UPS output testing, what does proper automatic voltage regulation (AVR) function demonstrate? → Output voltage remains within specification despite input voltage variations
27. What level of PPE is required when performing battery acceptance or maintenance testing regardless of the system voltage? → Face shield, chemical-resistant gloves, and insulated tools at minimum
28. What is the primary purpose of NFPA 70E? → To reduce electrical hazards and ensure safe work practices
29. Kirchhoff's Voltage Law (KVL) states that: → The algebraic sum of all voltages around any closed loop equals zero
30. What is the role of a digital multimeter in field testing? → To measure basic electrical parameters