Final answer:
The Thury system pertains to the transmission of electrical power at high voltages, typically from 120 kV to 700 kV, to decrease energy losses in long-distance transmission and is stepped down for safe local distribution.
Step-by-step explanation:
The question refers to the Thury system, which is an electrical engineering concept. Electric power is generated at a power plant, typically at voltages greater than 10 kV (kilovolts), and then transmitted over long distances at high voltages to minimize energy losses. Voltages for long-distance transmission often range from 120 kV to 700 kV, with local power distribution involving further stepping down of voltage through substations. At these substations, the voltage is reduced for safe use in residential or commercial areas to levels such as 120 V, 240 V, or 480 V. The transmission of electricity at higher voltages allows for the delivery of the same power with lower current, which reduces the power loss due to the resistance of the transmission lines.