Multiple Choice Questions are very important for different competitive examinations. Also, we call these as MCQs in short. Again, some of us call these as objective type questions. So, we have provided such questions for betterment of preparation for such examinations. The subject of electrical machines is the backbone of electrical engineering. We can categories electrical machines as ac machines and dc machines. Again dc machines have two groups. These are dc motors and dc generators. Hence, we can understand that the Multiple Choice Questions or MCQs on DC Machines(MCQs) are very essential to study.
Importance of Multiple Choice Questions (MCQs) on DC Machines
For clearing different engineering examinations we need to practice such questions in deep. We have provided explanations for each answer. No book will provide you such readymade explanations of the answers in such a compact form. We have not segregated the MCQs as per motor and generator. There are mixtures of such questions but all are related to DC machines only. We continually, research for finding out new conceptual questions and try to provide here for your purposes.
Why online Multiple Choice Questions (MCQs) on DC Machines are essential?
Nowadays, most of the competitive examinations are in online mode. So practicing such MCQs online is the best process for preparing such examinations.
The Chapters of Multiple Choice Questions (MCQs) on DC Machines
This list is mainly about Multiple Choice Questions (MCQs) on DC Machines. So, we have covered all the possible sections of dc machines. For example, we have covered, the working principle of dc motors and working principle of dc generators. Then we have covered types of dc motor and also the types of dc generators. Also, we have included characteristics curves of dc motor and generator. In addition to these, we have included different multiple questions from testing of dc machines and their different applications. The speed control of dc motors and voltage regulation of dc generators are also provided. Many more have been provided along with their explanations.
MCQs on DC Machines
both brushes and commutator segments.
mechanical support to the poles.
cover to the whole machine.
path for the field magnetic flux.
all of above.
collect the armature current.
rectify the armature current.
amplify the output current.
collect and rectify the armature current.
Number of commutator segments = number of slots
Number of commutator segments > number of slots
Number of commutator segments < number of slots
Number of commutator segments = ½ of number of slots
approaches to zero.
approaches to infinity.
does not change.
air gap flux.
electrical input power.
Induced emf in the armature.
to spread out the flux in air gap.
to provide larger cross section to flux path for reducing reluctance.
to hold the field coil in place.
all of above.
output voltage and armature current.
armature emf and armature current.
armature emf and field current.
output voltage and field current.
product of armature current and back emf.
input power – losses.
product of efficiency and output power.
power output + iron losses.
reduce the weight of the core.
safe the steal for lamination.
balance the weight of the core for balanced rotational motion.
ventilate air during rotation.
is more than supply voltage.
is added to the supply voltage.
helps in energy conversation.
regulates its armature voltage.
the speed of the motor becomes excessively high.
the motor gets stopped instantly.
the motor gets tripped.
the motor will continue to rotate but with a reduced speed.
both field flux and back emf.