Electrical Machine MCQs for test preparation. Includes multiple-choice questions and answers on electrical machines, providing a comprehensive resource for students and professionals.
Which of the following adds to the pitch of the commutator ?
A. Number of commutator segments between two successive coilsB. The distance between the staring of first coil and its next successive coilC. Number of conductors spanned by one coil at the back end of the armatureD. Number of conductors spanned by one coil at the front end of the armature
Four pole lap winding is used in DC machines. How many parallel routes are there ?
A. 2B. 3C. 4D. 6
Windings on DC machines are ____ ?
A. short pitchedB. full pitchedC. either of theseD. None of them
Which of the following windings is required for every DC machine ?
A. open type windingB. closed windingC. lap windingD. wave winding
Which of the following bearings are suitable for the reason ?
A. roller bearings → large machinesB. ball bearings → small machinesC. neither 1 nor 2D. Both a and b
Which of the following brush types and how they should be used is/are right:
A. copper graphite → low voltage high current densityB. carbon brush → normal ratingsC. electro graphite → large ratingsD. All of them
In DC generators brushes are used for _____ ?
A. reduce eddy current lossB. convert ac armature current in to dcC. collecting of current without any sparkingsD. collecting of voltage
A DC machine uses seventy-two coils. Determine the necessary number of commutator segments.
A. 13B. 45C. 36D. 72
In DC machine yoke offers ___ ?
A. flux path completionB. mechanical protection to the machineC. produce working fluxD. Both A and B
A DC generator without commutator is a ____ ?
A. DC generatorB. induction motorC. DC motorD. AC generator