Answer / m. ahatesham shaikh

mostly electrical power is generated by running alternators with the help mechanical turbine. and turbines gives best efficiency in the speed range of 3000rpm to 3600rpm.
and frequency of generated electricity is given by
f=((P*N)/120)Hz, P= No. of poles of alternator, N= Speed in rpm.
and mostly 2 poles alternators are used.
therefore ((2*3000/)/120)=50
that's why some countries have selected 50Hz (using 3000rpm) and some 60Hz (3600rpm).
and India has selected 50Hz using 3000rpm.

Answer / post master

because we carry the British legacy.

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