Communication line 80 km long operates at 30V. When a short occurred on the line, the voltmeter reading became 24V.

Communication line 80 km long operates at 30V. When a short occurred on the line, the voltmeter reading became 24V. At what distance did the short circuit occur?

Let us determine the current passing through the communication line according to Ohm’s law, the resistivity of the line will be taken into account as a unit per kilometer, relative to the given kilometers of the line:

I = U / 80 = 30/80 = 0.375 A. Knowing the current flowing through the line and the voltage in the line, we determine at what distance the loop was formed.

L = 24 / 0.375 = 64 km.

Answer: The communication line was short-circuited at 64 kilometers.