LATEST 2025 Master Electrician Practice Exams with answers

When exceptions are not a consideration, the MINIMUM size overhead service-drop conductors shall be copper. A. 6 AWG B. 8 AWG C. 12 AWG D. 14 AWG Here the "question" is in the form of fill in the blank and your task is to select the choice that best completes the statement. In this case, exceptions are not applicable. You have to select the minimum size conductor required for overhead service-drop conductors. You should have selected B because Section 230.23(B) specifies that the conductors shall not be smaller than 8 AWG copper. HOW TO USE THESE TESTS To get the most out of these tests you should answer every question and highlight your NEC for future reference. If you have difficulty with a question and cannot come up with the answer that is familiar to you, make note of the question and come back to it after completing the remainder of the questions. Review your answers with the ANSWER KEY after completing the test. This will help you identify your strengths and weaknesses. When you discover you are weaker in some areas than others, you will know that further study is necessary in those areas. Do not try to study for too long a period of time, if you do, you may get fatigued and get burned out. This also helps you develop good study habits. GOOD LUCK! TOP Digitally Monitored for Compliance with License Terms © Ray Holder 6 Useful Formulas To Find Single Phase Three Phase Direct Current Amperes when kVA is known kVA x 1,000 E kVA x 1,000 E x 1.732 not applicable Amperes when horsepower is known HP x 746 E x %Eff. x PF. HP x 746_ E x 1.732 x %Eff. x PF. HP x 746 E x %Eff. Amperes when Kilowatts are known kW x 1,000 E x PF. kW x 1,000 E x 1.732 x PF. kW x 1,000 E Kilowatts I x E x PF. 1,000 I x E x 1.732 x PF. 1,000 I x E_ 1,000 Kilovolt Amperes I x E_ 1,000 I x E x 1.732 1,000 not applicable Horsepower I x E x %Eff. x PF. 746 I x E x 1.732 x %Eff. x PF. 746 I x E x %Eff. 746 Watts E x I x PF. E x I x 1.732 x PF. E x I I = Amperes HP = Horsepower E = Volt %Eff. = Percent Efficiency kW = Kilowatts PF = Power Factor kVA = Kilovolt-Amperes TOP Digitally Monitored for Compliance with License Terms © Ray Holder 7 Power – “Pie” Circle Formulas Ohms Law Circle Formulas TOP Digitally Monitored for Compliance with License Terms © Ray Holder 8 POWER FACTOR FORMULAS TOP Digitally Monitored for Compliance with License Terms © Ray Holder 9 VOLTAGE DROP FORMULAS Formula Definitions: VD = Volts dropped from a circuit. 2 = Multiplying factor for single-phase circuits. The 2 represents the conductor length in a single-phase circuit. 1.732 = Multiplying factor for three-phase circuits. The square root of 3 represents the conductor length in a three-phase circuit. The only difference between the single-phase and three-phase formulas is that “1.732” has replaced “2”. K = Approximate resistivity of the conductor per mil foot. A mil foot is a wire 1 foot long and one mil in diameter. The approximate K value for copper wire is 12.9 ohms and for aluminum wire is 21.2 ohms per mil foot. I = Current or amperage draw of the load. D = The distance from the source voltage to the load. CM = Circular mil area of the conductor. (Chapter 9, Table 8) *NOTE – When determining wire size, distance or current, VD is the actual volts that can be dropped from the circuit. The recommended percentage for a branch-circuit is 3%. Example: 3% of 120 volts is 3.6 volts. DO NOT enter 3% in the VD position. To find voltage drop in a single-phase circuit. VD = 2 x K x I x D CM To find wire size in a single-phase circuit. CM = 2 x K x I x D VD To find distance in a single-phase circuit. D = CM x VD_ 2 x K x I To find MAXIMUM current in amperesin a single-phase circuit. I = CM x VD_ 2 x K x D