Electrical Engineering · Question Bank

DC Motors

208 of 285 questions match · page 7 of 11. Answer in your head first, then check the solution.

📘 EE Mock Board Exam
TypeAll 285Problem solving 77Objective 208
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#121📘 EE Pocket Reviewer RojasEasy
The armature current drawn by a dc motor is proportional to which of the following?
ATorque of the motor
BFlux in the field poles of the motor
CSupply voltage of the motor
DSpeed of the motor
#122📘 EE Pocket Reviewer RojasEasy
What type of dc motor is used in vacuum cleaners?
AShunt motor
BSeries motor
CCumulative compound motor
DDifferential compound motor
#123📘 EE Pocket Reviewer RojasEasy
What will happen if a series motor is started without a load?
AThe starting torque is very high
BThe starting current is very high
CThe starting speed is very high
DAll of these
#124📘 EE Pocket Reviewer RojasEasy
Which loss occurs in the yoke of a dc motor?
AIron loss
BCopper loss
CFriction and windage loss
DNo loss
#125📘 EE Pocket Reviewer RojasEasy
When load is increased, what will happen to the speed of a dc shunt motor?
AIt will reduce slightly
BIt will remain constant
CIt will also increase proportionately
DIt will increase slightly
#126📘 EE Pocket Reviewer RojasEasy
The Ward-Leonard system of speed controls can't be used in which of the following applications?
AVery low speed
BFrequent motor reversals
CConstant speed operation
DWide speed range
#127📘 EE Pocket Reviewer RojasEasy
Which of the following dc motors are used in heavy starting torque loads?
ASeries motors
BShunt motors
CLong-shunt compound motors
DShort-shunt compound motors
#128📘 EE Pocket Reviewer RojasEasy
What will happen if the back emf of a dc motor is not present?
AThe motor will burn
BThe motor will not run
CThe motor will run at very high speed
DThe motor will run at very low speed
#129📘 EE Pocket Reviewer RojasEasy
At present, dc motors are widely used in which of the following applications?
AAir compressors
BMachine shops
CElectric traction
DPumps
#130📘 EE Pocket Reviewer RojasEasy
Which of the following dc motors is best for high starting torque load applications?
ASeries motors
BShunt motors
CCumulative compound motors
DDifferential compound motors
#131📘 EE Pocket Reviewer RojasEasy
Which of the following motor bearings should be oiled regularly?
ABall bearings
BSleeve bearings
CBoth A and B
DNone of these
#132📘 EE Pocket Reviewer RojasEasy
What is the meaning of the power stated in the nameplate of a dc motor?
AIt is the power drawn from the supply lines
BIt is the gross power that can be developed
CIt is the power output from the shaft
DIt is the maximum power that can be supplied to the motor
#133📘 EE Pocket Reviewer RojasEasy
Which dc motors is commonly used in rolling mills?
ASeries motors
BShunt motors
CCumulative compound motors
DDifferential compound motors
#134📘 EE Pocket Reviewer RojasEasy
Which motor is best suited to drive ceiling fans?
AUniversal motor
BCapacitor start and run motor
CPermanent capacitor motor
DCapacitor start motor
#135📘 EE Pocket Reviewer RojasEasy
Which of the following can reverse the direction of rotation of a universal motor?
AInterchange the brush leads
BReverse the supply terminals
CChange the supply voltage, like from ac to dc
DIt cannot be reversed
#136📘 EE Pocket Reviewer RojasEasy
A capacitor-start, capacitor-run single-phase motor is basically which types of motor?
AAn ac series motor
BA single-phase synchronous motor
CA two-phase induction motor
DA dc series motor
#137📘 EE Pocket Reviewer RojasEasy
What is the type of capacitor used in a capacitor start induction motor?
APaper capacitor
BCeramic capacitor
CElectrolytic capacitor
DMica capacitor
#138📘 EE Pocket Reviewer RojasEasy
Which of the following single-phase motors has rotors without a winding?
ARepulsion motor
BUniversal motor
CReluctance motor
DHysteresis motor
#139📘 EE Pocket Reviewer RojasEasy
The purpose of the centrifugal switch is to disconnect the starting winding after ____
AThe rotor is run about 30 to 45 seconds
BThe rotor is run about 2 to 3 minutes
CThe rotor has picked up its rated speed
DThe rotor has picked up about 70 to 80% of its rated speed
#140📘 EE Pocket Reviewer RojasEasy
What is the purpose of the starting winding in a single-phase induction motor?
AIt is used to reduce the losses at start
BIt is used to control the magnitude of the starting current
CIt is used to produce a rotating flux in conjunction with the main winding
DIt is used to protect the motor from overspeeding at starting instant

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