Question { L&T, 26817 }

What is the difference between EARTH & NEUTRAL?

Answer

neutral is generated in star connections & in three phase
it playas an important role in balancing the voltage.

and the earthing is low resistance path for flow of an
current. which is obtained from earth by earth electrode.

Question { 9549 }

why 3 phase motors are preferable over single phase motors ?

Answer

in the three phase motor at less power& current the motor
will work with good efficiency than the single phase motor

Question { APTransco, 43869 }

WHERE IS THE LIGHTING ARRESTER SHOULD BE PLACED IN
DISTRIBUTION LINES?

Answer

an earth wire is being carried with the power lines, which
is at the top most of lines, that of (R,Y,B).
(this earth wire acts as an lightning arrester.

lightning arrester is also installed on the poles.

Question { Bhel, 8565 }

the input mechanical power of a single alternator is
increased,its RPM increased but in case of an alternator
synchronised with grid its RPM does not increased with
increase of input mechanical power. why?

Answer

it because the alternator it ynchronoed with the grid & it
output it to be kept constant as per grid ( Volt, frequency ),
frequency changes as there i an change in speed