Electrical Machines Practice Test 2

1. In dc machine iron losses cause _________

2. A peaky voltage supply is given to the 3 phase power transformer of the connection power system. These results into ____________

3. Which of the following equations represents the RMS value of the generated EMF in a short-pitched N-turn armature coil of an AC machine ____________

4. The armature rotation in the dc machine and the magnetic field are independent of each other and obey laws of conservation of energy.

5. For a four pole, 16 slot armature with two coil-side/slot having lap connected progressive winding has single turn coils. The same machine is then wave wound, the emf induced in the lap wound dc machine to that of wave wound will be ________

6. If two series motors are identically coupled. One is running as motor while other as generator. For this combination, the iron losses and frictional losses are found identical for _________

7. A 3-phase synchronous alternator is connected to the infinite bus is over excited, that corresponds to ______________

8. If the dimensions of all the parts of a synchronous generator and the number of field and armature turns are doubled, then the generated voltage will change by a factor of ________

9. The dc series generator is employed as ____________

10. For squirrel cage and slip ring induction motor, cooling methods is efficient in _________