For tramways circuit the return path is Through rails.
For tramways, the return path for electric current is often through the rails themselves, which act as a conductor. This is known as the "track return" or "running rails return" system.
In this system, the electric current flows from the power source, through the overhead wires or third rail, to the electric motor on the tram, and then returns to the power source through the rails.
The rails are connected to the substation and provide a low-resistance path for the electric current to flow back to the source.
This method of return path is efficient and cost-effective for tramways, as it eliminates the need for a separate conductor to carry the return current.
It also helps to reduce the overall electrical resistance in the circuit, which can improve the efficiency and performance of the tramway system. However, it requires careful maintenance and insulation of the rails to prevent electrical shocks or short circuits.