Electrical Engineering · Question Bank
DC Generators
127 of 196 questions match · page 3 of 7. Answer in your head first, then check the solution.
#41📘 EE Pocket Reviewer RojasEasy
What do you mean by “flashing” in a dc generator?
ATo increase the flux density by adding more turns in the field poles
BTo create residual magnetism by a dc source
CTo perform a short circuit test in the generator
DTo increase the excitation current in the field by lowering the rheostat resistance
#42📘 EE Pocket Reviewer RojasEasy
Equalizer connections are required when connecting two or more what type of dc generators?
ASeries generators
BShunt generators
CCompound generators
DAll of these
#43📘 EE Pocket Reviewer RojasEasy
In dc generators, the wave windings are used in which applications?
ALow voltage and low current
BHigh voltage and high current
CLow voltage and high current
DHigh voltage and low current
#44📘 EE Pocket Reviewer RojasEasy
What is the reason why dc generators are installed near the load center?
ATo reduce the iron losses
BTo reduce the sparking at the brushes
CTo reduce the corona losses
DTo reduce the line losses
#45📘 EE Pocket Reviewer RojasEasy
What is the probable cause why a dc generator gives electric shock upon touching its body?
AWeak insulation on the armature coils
BLoose earth wire
CGrounded armature coils
DAll of these
#46📘 EE Pocket Reviewer RojasEasy
What is the proper color of a commutator?
AGlazed chocolate
BDark brown
CReddish brown
DShiny brown
#47📘 EE Pocket Reviewer RojasEasy
What is the coupling field between electrical and mechanical systems of a dc machine?
AElectric field
BMagnetic field
CMechanical field
DAll of these
#48📘 EE Pocket Reviewer RojasEasy
What is the effect of the armature magnetic field to the main magnetic field?
AIt will demagnetize or weakens the main field
BIt will cross magnetize or distort the main field
CIt will magnetize or strengthen the main field
DBoth A and B
#49📘 EE Pocket Reviewer RojasEasy
In the commutation process which of the following is getting reversed?
ACurrent
BVoltage
CPower
DAll of these
#50📘 EE Pocket Reviewer RojasEasy
Which of the following is a simple method of increasing the voltage of a dc generator?
AIncrease the length of armature
BIncrease the air gap of flux density
CIncrease the load on the generator
DIncrease the speed of rotation
#51📘 EE Pocket Reviewer RojasEasy
How do you call the armature winding pitch in which the coil sides are a pole pitch apart?
AFull pitch
BFractional pitch
CPole pitch
DUnity pitch
#52📘 EE Pocket Reviewer RojasEasy
In dc generators, the generated emf is directly proportional to which of the following?
ANumber of armature current paths
BField current
CPole flux
DNumber of dummy coils in the armature
#53📘 EE Pocket Reviewer RojasEasy
What is the purpose of placing the armature windings of the dc generator on the rotor?
ATo save the iron
BTo reduce the losses
CTo reduce the armature reaction
DTo facilitate commutation
#54📘 EE Pocket Reviewer RojasEasy
What is the classification of a dc generator that receives its field excitation from internal source?
ASelf-excited
BSeparately excited
CInternally excited
DUnder excited
#55📘 EE Pocket Reviewer RojasEasy
DC generators works on the principle of ____
AFleming's left hand rule
BFleming's right hand rule
CLenz’ law
DJoule’s law
#56📘 EE Pocket Reviewer RojasEasy
What is the major effect of the phenomenon called “armature reaction”?
AIt can cause the total flux to decrease
BIt can cause partial short circuit in the armature
CIt can cause the armature core to run wild
DIt can cause big power loss in the armature
#57📘 EE Pocket Reviewer RojasEasy
What is the main function of the interpoles in a dc generator?
ATo minimize friction between brushes and commutator
BTo minimize wear and tear between brushes and commutator
CTo minimize sparking between the brushes and the commutator
DNone of these
#58📘 EE Pocket Reviewer RojasEasy
Which of the following dc generators are suitable for running in parallel?
ASeries generators
BShunt generators
CCompound generators
DAny of these
#59📘 EE Pocket Reviewer RojasEasy
How does an interpole winding be connected in a dc generator?
AIn series with the armature windings
BIn parallel with the field winding
CIn series with the field windings
DIn parallel with the armature windings
#60📘 EE Pocket Reviewer RojasEasy
An “exciting current” is one that is required in which of the following?
ATo create a magnetic field
BTo charge a battery
CTo excite a synchronous motor
DTo build up a dead circuit
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