Which formula is used to calculate voltage drop for a single-phase circuit?

The formula for calculating voltage drop in a single-phase circuit is crucial for ensuring that the voltage supplied to electrical devices is within acceptable limits. The correct formula incorporates DC resistance because the resistance of the conductor affects how much voltage is lost due to the current flowing through it.

In single-phase circuits, the voltage drop can be determined using the factors of DC resistance, current, and the length of the wire run. The correct formula reflects that voltage drop (Vd) is directly proportional to the resistance of the conductor, the current flowing through it, and the length of the circuit. The factor of "2" in the formula signifies that the current must travel to the load and back, effectively doubling the resistance encountered. Furthermore, dividing by "1000" adjusts the result to a more practical and commonly used unit for expressing voltage drop, typically in volts, over a distance measured in feet or meters.

The choice that combines all these elements appropriately computes the voltage drop for the specific scenario, making it the correct option. In contrast, other formulas either lack essential factors, misrepresent the relationship between the variables, or are not applicable for the context of single-phase circuits. This understanding is fundamental to ensuring electrical circuits are designed within safe operational parameters.