What type of excitation is given to the rotor winding of a synchronous motor?

What type of excitation is given to the rotor winding of a synchronous motor? 

(A) DC supply at 100 -250 V (B) AC supply at 400 V (C) Revolving field (D) Induction from stator currents 
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1 Answer

Answer :

Dc supply of 100 to 250v is applied on the field circuit to make stable magnetic field which thens follow the rotating magnetic feild of stator or armature circuit.
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