Question

At what voltage is the electric power from the generating station transmitted?
A. 200kV
B. 11kV
C. 220V
D. 220kV

Answer 1

Hint: The power plants typically produce 50Hz, alternating-current (AC) electricity with voltages between 11 kV and 33 kV. At the power plant site, the 3-phase voltage is stepped up to a higher voltage for transmission on cables strung on cross-country towers to minimize the losses and increase efficiency.

Complete step by step answer:
High voltage (HV) and extra high voltage (EHV) transmission is the next stage from power plant to transport A.C. power over long distances at voltages like 220 kV and 400 kV and with small current by minimizing the losses.
Where transmission is over a large distance over 1000km, high voltage direct current transmission is also favoured to minimize the losses. Sub-transmission network at 132 kV, 110 kV, 66 kV or 33 kV constitutes the next link till the user.
Hence, the voltage the electric power is generated at the power generating station is 11 kV.
So, the correct answer is (B) 11kV.

Note:Alternating Voltage generated in power stations are always preferred because:

I. Alternating voltages can be stepped up or down very easily by using step-up and step-down transformers.
II. Alternating voltages can be transmitted over long distances at voltages like 220 kV and 400 kV and with small current which minimizes losses and increases efficiency.