If several resistors are connected in series in a circuit,
a portion of the total voltage drops at the individual resistors.
This also applies to the connection line, which connects the load to the voltage source.

The wire resistance is in series connection with the load.
The voltage drop on the wire that is lost to the load is called the loss voltage.

\(Loss\, Voltage = Current ยท Wire\, Resistance\)

\(U_V=I·R_L\)

The useful voltage acting on the load corresponds to the terminal voltage minus the
voltage loss caused by the line resistance.

\(Effective\, Voltage= Clamping\, Voltage - Voltage\, loss\)

\(\displaystyle U_N=U-U_V=U-I·R_L\)

According to the formula \(U_V=I·R_L\) the loss voltage depends on the current \(I\)
and the line resistance \(R_L\).

The wire resistance is the greater the length \(l\) and the smaller the line cross section \(A\) is.

The wire resistance is calculated according to the formula

for one wire length \(\displaystyle R_L=\frac{ρ·l}{A}\)

for outgoing and return line \(\displaystyle R_L=\frac{ρ·2l}{A}\)

* \(ρ\) stands for the specific resistance of the line.

The loss voltage is calculated according to the formula