Which of the following is not a factor when calculating voltage drop?

The size of the conduit is not a factor when calculating voltage drop because voltage drop calculations focus specifically on the electrical characteristics of the conductor itself, such as its length, the current flowing through it, and its resistance.

Length of the conductor is crucial because the longer the conductor, the higher the resistance encountered, which affects the overall voltage drop. The current flowing through the conductor is also essential, as a higher current results in a greater voltage drop due to the conductor's resistance. Additionally, the resistance of the conductor is a key element in determining how much voltage is lost along the length of the conductor under load.

In contrast, the size of the conduit relates to its physical dimensions and the protection and housing of the conductors, but it does not directly impact the electrical parameters that determine voltage drop.