Question

What part of the utility system supplies distribution substations from bulk power sources?

(A) Transmission lines
(B) Distribution lines
(C) Transformers
(D) Generators

Answer 1

Transmission lines carry high voltage electricity from bulk power sources to distribution substations where it is stepped down for local distribution.

Step-by-step explanation:

The part of the utility system that supplies distribution substations from bulk power sources is the transmission lines. Transmission lines are essential for transmission along power lines at high voltages, often hundreds of kilovolts, to reduce power losses over long distances. As electric power is usually generated at voltages greater than 10 kV, it needs to be transmitted at higher voltages, such as over 200 kV and up to 700 kV, before being stepped down at the substations closer to the point of use to voltages like 5 to 13 kV and then further reduced for residential or commercial use to 120, 240, or 480 V for safety.