Why we are use 11KV / 22KV / 33KV / 66KV / 110KV / 230KV /
440KV this type of ratio. why cant we use other voltage
ratio like 54KV / 99KV et.,

Answer Posted / sagar khandey

When an alternator generates voltage, we always use a
multiple of 1.11 because for a pure sine wave the FORM
FACTOR is the ratio of rms value of voltage or current with
the avg. value of voltage or current and for pure sine wave
rms value of current is Imax/root '2' and avg. value is
2Imax/pie and which comes out to be 1.1;

We can't have a combination of other then a multiple of 1.11*.
So we can see all the voltages are made inevitably multiple
of this value (1.1, which is the form factor of ac wave).

Also it provides us the best economic construction of step
up and step down transformers.


In the case of a Square Wave ie. a digital wave, the RMS and
the average value are equal; therefore, the form factor is 1.

Is This Answer Correct ?    10 Yes 6 No



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