Home / EEE / D.C. Generators :: section-1

EEE :: D.C. Generators

  1. In a level compounded D.C. generator, full load terminal voltage is

  2. A.

     Negligibly low

    B.

     Equal to no-load terminal voltage

    C.

     More than no-load terminal voltage

    D.

     Less than no-load terminal voltage


  3. In D.C. generators the pole shoes are fastened to the pole core by

  4. A.

     Rivets

    B.

     Counter sunk screws

    C.

     Brazing

    D.

     Welding


  5. Which generator would you prefer for feeding long D.C. transmission lines?

  6. A.

     Series generator

    B.

     Shunt generator

    C.

     Over compound generator

    D.

     Flat compound generator


  7. In D.C. generators, lap winding is used for

  8. A.

     High voltage, high current

    B.

     Low voltage, high current

    C.

     High voltage, low current

    D.

     Low voltage, low current


  9. Copper brushes in D.C. machine are used

  10. A.

     Where low voltage and high currents are involved

    B.

     Where high voltage and small currents are involved

    C.

     In both of the above cases

    D.

     In none of the above cases


  11. A shunt generator running at 1000 r.p.m. has generated e.m.f. as 200 V. If the speed increases to 1200 r.p.m., the generated e.m.f. will be nearly

  12. A.

     150 V

    B.

     175 V

    C.

     240 V

    D.

     290 V


  13. For both lap and wave windings, there are as many commutator bars as the number of

  14. A.

     Slots

    B.

     Armature conductors

    C.

     Winding elements

    D.

     Poles


  15. Armature reaction of an unsaturated D.C. machine is

  16. A.

     Cross-magnetizing

    B.

     Demagnetizing

    C.

     Magnetizing

    D.

     None of above


  17. 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

  18. A.

     2 : 3

    B.

     3 : 1

    C.

     3 : 2

    D.

     1 : 3


  19. A shunt generator can self-excite

  20. 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 of the above