Electrical Machines
Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are

 2, 4 ,5
 2, 3 , 5
 1, 4
 1, 3, 5

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Which of the following is done in speed control of DC motor by field flux control?

 Inserting an additional resistance in the armature circuit.
 Inserting an additional resistance in the field circuit.
 Any of above.
 Inserting resistance to armature circuit and field circuit.

ANSWER DOWNLOAD EXAMIANS APP