Electrician Cheat Sheet 2026

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

1. A transformer has a primary voltage of 480V and a turns ratio of 4:1. What is the secondary voltage? → 120V
2. What is the NEC requirement for the minimum working space depth in front of a 120/240V residential panel? → 30 inches
3. What is the formula for calculating the area of a circle (used for conduit fill calculations)? → A = πr²
4. What OSHA citation is typically issued when an employer's violation of a safety standard could cause death or serious physical harm? → Serious violation
5. What is the impedance of a circuit with 8 ohms resistance and 6 ohms reactance? → 10 ohms
6. What color is typically used for safety labels indicating an electrical shock hazard? → Orange and black
7. Under the NEC, AFCI protection is now required in which residential room? → Bedroom
8. What type of grounding electrode is considered the most effective? → Concrete-encased electrode (Ufer ground)
9. What does NEMA stand for in the context of motor control enclosures? → National Electrical Manufacturers Association
10. What is the purpose of a control transformer in a motor control circuit? → To provide a lower, safer voltage (typically 120V) for the control circuit
11. What is the minimum bending radius for 1-inch EMT? → 6 inches
12. What is the maximum rating of an inverse time circuit breaker used to protect a motor branch circuit per the NEC? → 250% of motor FLC
13. What size knockout is required in an electrical box for 3/4-inch conduit? → 3/4 inch
14. What is the purpose of a GFCI device from a safety perspective? → To protect people from electric shock by detecting ground faults as small as 5 milliamps
15. Under the NEC, bonding of metal water piping systems is required when the piping is likely to become energized. What is this requirement found in? → Article 250
16. What is the nameplate 'service factor' of a motor? → The multiplier indicating how much above nameplate load the motor can handle continuously
17. In a series circuit, how does total resistance compare to individual resistors? → Total resistance is the sum of all resistors
18. Per NEC 250.53(B), what is the minimum separation required between two ground rod electrodes when more than one is installed? → 6 feet
19. What is the maximum percentage of conduit fill allowed for three or more conductors per NEC Chapter 9? → 40%
20. What is the minimum length for a ground rod? → 8 feet
21. A 240V, 5kW electric heater draws how many amps? → 20.8 amps
22. What is the first step in an arc flash hazard analysis? → Collecting electrical system data to determine incident energy levels
23. How is armored cable (Type AC) different from metal-clad cable (Type MC)? → MC has an aluminum bonding strip; AC uses an internal bare wire that provides fault return
24. In which location is it NOT permissible to connect neutral conductors and equipment grounding conductors together? → At a remote subpanel fed from the same service
25. What size fuse or breaker is typically used to protect a 200-amp service entrance? → 200 amps
26. What is the purpose of a wire nut (twist-on wire connector)? → To splice two or more conductors together
27. What is the maximum number of current-carrying conductors permitted in a single conduit before derating is required under the NEC? → 3
28. What is the purpose of Lockout/Tagout (LOTO) procedures? → To prevent accidental energization of equipment during maintenance
29. What is the minimum conductor size required for a ground ring grounding electrode per NEC 250.52(A)(4)? → 2 AWG bare copper
30. What is the frequency of standard AC power in the United States? → 60 Hz