Q. When an electric train is moving down a hill, the DC motor will operate as ____________

View solution

Q. Nowadays, DC motor is widely used only in ____________

View solution

Q. Which motor is preferred in highly explosive atmosphere?

View solution

Q. For which of the following operations a DC motor is preferred over an AC motor?

View solution

Q. The armature in DC machines is always placed on rotor because _______

View solution

Q. In a DC machine, rectification provided with commutator is ___________

View solution

Q. Commutator performs rectification so that output of the machine is bi-directional.

View solution

Q. Which of the following method is used to connect commutator segments to armature conductors?

View solution

Q. In D.C. generators, rapid brush ware causes due to _________

View solution

Q. What are the number of the brushes in the lap winding?

View solution

Q. When Copper brushes are used in DC machine?

View solution

Q. In DC generators, current is fed up to the external circuit from armature through _______

View solution

Q. What are the number of the brushes in the wave winding?

View solution

Q. Which conductors are in point of contact with brushes?

View solution

Q. In case of DC machine winding, number of commutator segments is equal to ______

View solution

Q. How total number of brushes in a commutator are determined in a given DC machine?

View solution

Q. In a DC generator the ripples in the direct emf generated can be reduced by________

View solution

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

View solution

Q. What is the requirement of the good commutation?

View solution

Q. How to avoid grooves in the commutation of DC machine with the help of brush?

View solution