Why DC excitation is used for alternators? Why cant it be AC?

Answer Posted / hitesh parmar

If A.C. excitation is provided in the alternator, the flux
produced will be alternating and accordimg to faraday's law
of magnetism back emf will be induced in the rotor, which in
turn causes a A.C.current to flow and as we know whenever a
current carrying conductor is placed in a magneti field
experience a force thus the torque will be produced in the
opposite direction to that of rotor rotation and the 2nd
reason is that in will produced a alternating poles that we
don't want so we are using D.C excitation only

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