Licensed Electrical Contractor Electrical Theory & Fundamentals 4

Question 1

What is the purpose of a neutral conductor in a single-phase AC system?

Accepted Answer

Provides a return path for current to complete the circuit

Answer

The neutral conductor provides the return current path, completing the circuit back to the source transformer.

Question 2

What is 'apparent power' in an AC circuit and what unit is it measured in?

Accepted Answer

The product of RMS voltage and RMS current, measured in volt-amperes (VA)

Answer

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.

Question 3

A conductor's resistance is affected by all of the following EXCEPT:

Accepted Answer

Color of the insulation

Answer

Conductor resistance depends on length, cross-sectional area, material resistivity, and temperature — insulation color has no effect on resistance.

Question 4

What is the peak voltage of a 120V RMS AC supply?

Accepted Answer

170 V

Answer

Peak voltage = RMS × √2 = 120 × 1.414 ≈ 170 V.

Question 5

What does Kirchhoff's Current Law (KCL) state?

Accepted Answer

The total current entering a node equals the total current leaving it

Answer

KCL states that the algebraic sum of all currents at any node (junction) in a circuit equals zero — current in equals current out.

Licensed Electrical Contractor Practice Test

Licensed Electrical Contractor Practice Test

Licensed Electrical Contractor Electrical Theory & Fundamentals 4