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EEE :: D.C. Generators

  1. In a D.C. generator

  2. A.

     External resistance = internal characteristic armature reaction

    B.

     Internal characteristic = magnetization characteristic ohmic drop

    C.

     External characteristic = magnetization characteristic ohmic drop armature reaction

    D.

     Magnetization characteristic = external characteristic


  3. The terminal voltage of a series generator is 150 V when the load current is 5 A. If the load current is increased to 10 A, the terminal voltage will be

  4. A.

     150 V

    B.

     Less than 150 V

    C.

     Greater than 150 V

    D.

     None of the above


  5. The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be

  6. A.

     640 V

    B.

     620 V

    C.

     600 V

    D.

     580 V


  7. Shunt generators are most suited for stable parallel operation because of their

  8. A.

     rising voltage characteristics

    B.

     identical voltage characteristics

    C.

     drooping voltage characteristics

    D.

     linear voltage characteristics


  9. Permeance is the reciprocal of

  10. A.

     Flux density

    B.

     Reluctance

    C.

     Ampere turns

    D.

     Resistance


  11. The critical resistance of the D.C. generator is the resistance of

  12. A.

     Field

    B.

     Brushes

    C.

     Armature

    D.

     Load


  13. In D.C. generators, the brushes on commutator remain in contact with conductors which

  14. A.

     Lie under South Pole

    B.

     Lie under North Pole

    C.

     Lie under interpolar region

    D.

     Are farthest from the poles


  15. In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis, when

  16. A.

     There is no load on the generator

    B.

     The generator runs on full load

    C.

     The generator runs on overload

    D.

     The generator runs on designed speed


  17. With a D.C. generator which of the following regulation is preferred?

  18. A.

     100% regulation

    B.

     Infinite regulation

    C.

     50% regulation

    D.

     1% regulation


  19. A separately excited generator as compared to a self-excited generator

  20. A.

     Is amenable to better voltage control

    B.

     Is more stable

    C.

     Has exciting current independent of load current

    D.

     Has all above features