Objective Questions on Commutation in DC Machine

  1. The commutator segments are connected to the armature conductors by means of

    Under construction.

  2. In a DC generator the ripples in the direct emf generated are reduced by

    Under construction.

  3. Which of following components of a DC generator plays vital role for providing direct electric current of a DC generator ?

    Under construction.

  4. The voltage drop for which of the following types of brush can be expected to be least ?

    Under construction.

  5. Satisfactory commutation of DC machine requires

    Under construction.

  6. To achieve spark less commutation brushes of DC generator are rocked ahead so as to bring them

    Under construction.

  7. In a DC generator in order to reduce sparking at brushes, the self-induced emf in the coil is neutralized by all of the following except

    Under construction.

  8. The rapid wear of brushes takes place due to

    Under construction.

  9. Number of tappings for each equilizer ring is equal to

    Under construction.

  10. The terminal voltage of a DC shunt generator drops on load because of all of the following reasons except

    Under construction.

  11. In a DC generator sparking between brushes and commutator surface may be due to

    Under construction.

  12. The change in speed of a DC generator due to increased load is corrected by

    Under construction.

  13. Under commutation results in

    Under construction.

  14. In a DC shunt generator working on load, the brushes are moved forward in the direction of rotation, as a result of this, commutation will

    Under construction.

  15. Commutation in a DC machine may be explained as a process

    Under construction.

  16. Current in a coil undergoing commutation is not able to get reversed completely by the end of commutation period. It is due to

    Under construction.

  17. The self induced emf in the coil undergoing commutation is called the

    Under construction.

  18. Sparkless commutation can be achieved by employing

    Under Construction

  19. If the armature electric current is increased to double its previous value, and the time of commutation is halved, how will the reactance voltage vary ?

    Under construction.

  20. To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by

    Under construction.