Electrical Theory & Fundamentals Flashcards
7 cards from real Licensed Electrical Contractor practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electrical Theory & Fundamentals flashcards as text
What is the purpose of a neutral conductor in a single-phase AC system?
Answer: Provides a return path for current to complete the circuit
The neutral conductor provides the return current path, completing the circuit back to the source transformer.
What is 'apparent power' in an AC circuit and what unit is it measured in?
Answer: The product of RMS voltage and RMS current, measured in volt-amperes (VA)
Apparent power (S) is the product of RMS voltage and RMS current (S = V × I) and is measured in volt-amperes (VA), representing total power delivered by the source.
A conductor's resistance is affected by all of the following EXCEPT:
Answer: Color of the insulation
Conductor resistance depends on length, cross-sectional area, material resistivity, and temperature — insulation color has no effect on resistance.
What is the peak voltage of a 120V RMS AC supply?
Answer: 170 V
Peak voltage = RMS × √2 = 120 × 1.414 ≈ 170 V.
What does Kirchhoff's Current Law (KCL) state?
Answer: The total current entering a node equals the total current leaving it
KCL states that the algebraic sum of all currents at any node (junction) in a circuit equals zero — current in equals current out.
What is the frequency of standard US residential AC power?
Answer: 60 Hz
Standard US residential and commercial power operates at 60 Hz, meaning the AC cycle completes 60 times per second.
In a capacitive circuit, how does current relate to voltage in terms of phase?
Answer: Current leads voltage by 90°
In a purely capacitive circuit, current leads voltage by 90° because the capacitor must charge before voltage builds across it.