Which factor does NOT directly influence the effective value of a voltage line?

The effective value of a voltage line is primarily determined by factors directly relevant to the electrical characteristics of the line being measured, such as its line type, ambient temperature, and voltage rating. The length of the line, while it may have indirect effects on other attributes like resistance and potential losses, does not directly influence the effective value of the voltage itself.

When considering line type, it refers to how the line is constructed and the materials used, which can affect the line's impedance and reactive properties, consequently impacting the effective voltage delivered along the line. Ambient temperature can affect the resistance of conductors, which in turn can influence voltage drop and overall efficiency. The voltage rating indicates the maximum voltage that a line can handle without risk of failure, thus establishing the effective operating bounds for the voltage.

In summary, while the length of the line might relate to physical installation and potential losses, it does not change how the effective voltage value is calculated or understood in the context of electrical engineering principles.