Electrical Engineering · Question Bank

DC Generators

196 questions · page 8 of 10. Answer in your head first, then check the solution.

📘 EE Mock Board Exam
TypeAll 196Problem solving 69Objective 127
DifficultyAll 196Easy 146Medium 41Hard 9
#141📘 EE Pocket Reviewer RojasEasy
What type of bearing is used to support the rotor shaft in a dc generator?
AMagnetic bearings
BBush bearings
CNeedle bearings
DBall bearings
#142📘 EE Pocket Reviewer RojasEasy
Brushes in dc generators are made from which of the following?
ACarbon
BMica
CBronze
DCopper
#143📘 EE Pocket Reviewer RojasEasy
Residual magnetism is necessary is which type of generators?
ASeparately-excited generators
BSelf-excited generators
CHigh voltage alternators
DLow voltage generators
#144📘 EE Pocket Reviewer RojasEasy
Which of the following dc generators cannot build up on open circuit?
AShunt generator
BSeries generator
CShort shunt compound generator
DLong shunt compound generator
#145📘 EE Pocket Reviewer RojasEasy
A belt driven cumulative compounded dc generator is delivering power to the dc mains. If the belt snaps, which one will likely to happen?
AThe machine will run as a cumulative compound motor running in the same direction
BThe machine will run as a cumulative compound motor running in the opposite direction
CThe machine will run as a differential compound motor running in the opposite direction
DThe machine will run as a differential compound motor running in the same direction
#146📘 EE Pocket Reviewer RojasEasy
A dc generator has been exposed to water. Which of the following instruments would be used to determine if its safe to operate?
AA megger
BA voltmeter
CAn ammeter
DA wattmeter
#147📘 EE Pocket Reviewer RojasEasy
DC generator voltage is increased by which of the following?
ABy cutting-in field resistance
BBy cutting-out field resistance
CBy cutting-in armature resistance
DBy cutting-out armature resistance
#148📘 EE Pocket Reviewer RojasEasy
What is the material generally used for commutator brushes?
AMica
BCopper
CCast iron
DCarbon
#149📘 EE Pocket Reviewer RojasEasy
In a dc generator, the number of commutator segments is equal to which of the following?
ANumber of turns
BNumber of coils
CNumber of slots
DNumber of coil sides
#150📘 EE Pocket Reviewer RojasEasy
What is the purpose of using compensating windings in dc generators?
ATo neutralize the armature reaction
BTo reduce the eddy current loss
CTo provide path for circulating air
DTo decrease the reluctance of the magnetic path
#151📘 EE Pocket Reviewer RojasEasy
What is the voltage regulation of an overcompounded dc generator?
APositive
BNegative
CAlmost zero
DVery high
#152📘 EE Pocket Reviewer RojasEasy
Which of the following is used to connect the commutator segments to the armature conductors?
ABy brazing
BBy copper lugs
CBy insulation pads
DBy resistance wires
#153📘 EE Pocket Reviewer RojasEasy
Which dc generators has the poorest voltage regulation?
ASeries generator
BShunt generator
CLong shunt compound generator
DShort shunt compound generator
#154📘 EE Pocket Reviewer RojasEasy
Which of the following would cause sparking at the brushes in a dc generator?
AHigh mica
BDirty commutator
CGrooved commutator
DAll of these
#155📘 EE Pocket Reviewer RojasEasy
Which of the following is an essential requirement for stable parallel operation of dc generators?
ASame percentage regulation
BDrooping voltage characteristics
CSame kW output ratings
DSame no-load to full load speeds
#156📘 EE Pocket Reviewer RojasEasy
How do you call a compound generator that has a voltage rise from no-load to full load?
AFlat compounded
BUnder compounded
COver compounded
DUnder-flat compounded
#157📘 EE Pocket Reviewer RojasEasy
What is the output of a single loop dc generator?
ASteady ac
BSteady dc
CPulsating ac
DPulsating dc
#158📘 EE Pocket Reviewer RojasEasy
In a dc machine, the biggest eddy current loss occurs where?
AField poles
BYoke
CArmature core
DCommutating poles
#159📘 EE Pocket Reviewer RojasEasy
Which of the following load characteristics is a good application of a shunt generator?
AConstant voltage over a wide range of load
BConstant voltage over a narrow range of load
CConstant current over a wide range of load
DConstant current over a narrow-range of load
#160📘 EE Pocket Reviewer RojasEasy
How can the ripples of output voltage in a dc generator be reduced?
AUse commutator with more segments
BUse bigger size of armature conductors
CUse more brushes
DUse equalizer rings

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