If a self excited D.C. generator after being installed, fails to build up on its first trial run, the first thing to do is to______________?

Related Mcqs:

1. A separately excited generator as compared to a self-excited generator_____________?

   A. is amenable to better voltage control
   B. is more stable
   C. has exciting current independent of load current
   D. has all above features

2. If a D.C. generator fails to build up the probable cause could not be_____________?

   A. imperfect brush contact
   B. field resistance less than the critical resistance
   C. no residual magnetism in the generator
   D. faulty shunt connections tending to reduce the residual magnetism

3. Two generators A and B have 6-poles each. Generator A has wave wound armature while generator B has lap wound armature. The ratio of the induced e.m.f. is generator A and B will be_______________?

   A. 2 : 3
   B. 3 : 1
   C. 3 : 2
   D. 1 : 3

4. In a separately excited generator supplying rated load the armature reaction.

   A. is always present
   B. is always absent
   C. may be sometimes present
   D. none of the above

5. The series field of a short-shunt D.C. generator is excited by_______________?

   A. external current
   B. armature current
   C. shunt current
   D. load current

6. Which of the following components of a D.C, generator plays vital role for providing direct current of a D.C. generator ?

   A. Dummy coils
   B. Commutator
   C. Eye bolt
   D. Equilizer rings

7. The e.m.f. generated by a shunt wound D.C. generator isE. Now while pole flux remains constant, if the speed of the generator is doubled, the e.m.f. generated will be_______________?

   A. E/2
   B. 2E
   C. slightly less than E
   D. E

8. Following D.C. generator will be in a position to build up without any residual magnetism in the poles______________?

   A. series generator
   B. shunt generator
   C. compound generator
   D. self-excited generator

9. A 220 V D.C. generator is run at full speed without any excitation. The open circuit voltage will be_____________?

   A. zero
   B. about 2 V
   C. about 50 V
   D. 220 V

10. A shunt generator can self-excite:_________________?

    A. only if the resistance of the field circuit is less than critical value
    B. only if the resistance of the field circuit is greater than critical value
    C. irrespective of the value of the resistance in the field circuit
    D. none