Question

At what voltage and frequency is the electric power generated at the power generating station ?

• A. $15kV$, $50Hz$
• B. $11kV$, $100Hz$
• C. $11kV$, $50Hz$
• D. $11kV$, $500Hz$

Answer 1

Answer: (C)

$11kV$, $50Hz$

The power plants typically produce 50 cycle/second (Hertz), 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.
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.
Where transmission is over 1000 kM, high voltage direct current transmission is also favored to minimize the losses. Sub-transmission network at 132 kV, 110 kV, 66 kV or 33 kV constitutes the next link towards the end user.
Hence, the voltage and frequency the electric power is generated at the power generating station are 11 kV and 50 hertz respectively.