The output of a substation largely depends on what factor of an industrial plant?

The output of a substation in relation to an industrial plant is influenced predominantly by the distance from the substation. This factor plays a crucial role because the farther a facility is from the substation, the greater the voltage drop that can occur during transmission. Losses in voltage can affect the efficiency and effectiveness of power delivered to the industrial machinery. Therefore, maintaining an optimal distance from the substation helps ensure that the voltage remains stable and that adequate power is delivered to support the operations of the plant.

While the other options might influence operations and efficiency in some capacity, they do not directly impact the electrical output from the substation in the same way that distance does. For instance, the number of machines or the type of equipment could affect the total power demand, but it's the distance that fundamentally affects how that power is transmitted and utilized. Similarly, the size of the facility can impact layout and design, but again, it does not have the same direct correlation with the output from the substation.