Electrical Machines In speed control of DC Series motor, speed lower than the rated speed can be obtained by Connecting an additional resistance in stator circuit. Connecting an additional resistance in the field circuit. Connecting an additional resistance in the armature circuit. Any of the above. Connecting an additional resistance in stator circuit. Connecting an additional resistance in the field circuit. Connecting an additional resistance in the armature circuit. Any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direction of rotation of DC motor is reversed by Interchanging armature and field connection. Adding resistance to field circuit. Reversing armature connection or field connection. Reversing supply connection. Interchanging armature and field connection. Adding resistance to field circuit. Reversing armature connection or field connection. Reversing supply connection. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The following statements relate to compensating winding (CW) and interpole winding (IW) of a dc machine : 1. CW neutralizes the armature reaction under a pole pitch 2. IW is connected in series with armature circuit 3. IW produces mmf in the commutating zone only 4. CWmmf is directed along the brush axis 5. Mmf produced by IW is equal to armature mmf From these, the correct statements are 1, 2, 3, 4 and 5 2, 3, 4, 5 1, 3, 4, 5 2, 3, 4 1, 2, 3, 4 and 5 2, 3, 4, 5 1, 3, 4, 5 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For pure resistive load what is the armature reaction? magnetization cross magnetization demagnetization All of these magnetization cross magnetization demagnetization All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The frame of an induction motor is made of aluminium. silicon steel. closed grained cast iron. stainless steel. aluminium. silicon steel. closed grained cast iron. stainless steel. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying supply voltage. Both (A) and (B). By varying number of poles. By varying the supply frequency. By varying supply voltage. Both (A) and (B). By varying number of poles. By varying the supply frequency. ANSWER DOWNLOAD EXAMIANS APP
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