Electrical Engineering · Question Bank

DC Motors

285 questions · page 13 of 15. Answer in your head first, then check the solution.

📘 EE Mock Board Exam
TypeAll 285Problem solving 77Objective 208
DifficultyAll 285Easy 218Medium 54Hard 13
#241📘 EE Pocket Reviewer RojasEasy
Which of the following single-phase ac motors is best suited for driving tape recorders and record players?
AShaded pole motor
BReluctance motor
CHysteresis motor
DSeries ac motor
#242📘 EE Pocket Reviewer RojasEasy
Which of the following is an outstanding feature of a universal motor?
AIt has best performance at low frequency
BIt has slow speed at all loads
CIt has excellent performance on dc supply
DIt has the highest output kW per kg ratio
#243📘 EE Pocket Reviewer RojasEasy
What type of rotors are used in single-phase motors?
ASquirrel-cage rotors
BWound rotors
CCommutator type rotors
DEither A or
#244📘 EE Pocket Reviewer RojasEasy
Which statements below describes a reluctance motor?
AIt is a variable torque motor
BIt is a low torque variable speed motor
CIt is a self starting type synchronous motor
DIt is a low noise, slow speed motor
#245📘 EE Pocket Reviewer RojasEasy
Which one is a disadvantage of a shaded pole motor?
AIts starting torque is low
BIt has very little overload capacity
CIt has low efficiency
DAll of these
#246📘 EE Pocket Reviewer RojasEasy
Which of the following motors is preferred for traction work?
AUniversal motor
BDC series motor
CSynchronous motor
DThree-phase induction motor
#247📘 EE Pocket Reviewer RojasEasy
What is the name of the device used to control a motor from a distant location?
AManual starter
BDrum switch
CSnap switch
DMagnetic controller
#248📘 EE Pocket Reviewer RojasEasy
Flame proof motors are used in which of the following applications?
APaper mills
BSteel mills
CMoist atmospheres
DExplosive atmospheres
#249📘 EE Pocket Reviewer RojasEasy
Which feature in selecting a motor to drive a centrifugal pump, will be of least significance?
AStarting characteristics
BSpeed control
COperating speed
DHorsepower
#250📘 EE Pocket Reviewer RojasEasy
Which of the following motors is preferred when smooth and precise speed control over a wide load range is required?
ADC motor
BSquirrel cage induction motor
CWound rotor induction motor
DSynchronous motor
#251📘 EE Pocket Reviewer RojasEasy
Lubricating grease is basically a combination of which of the following?
AVaseline and soap
BWater and soap
CGlycerine and soap
DOil and soap
#252📘 EE Pocket Reviewer RojasEasy
Which of the following motors is started using a pony motor?
AUniversal motor
BSynchronous motor
CInduction motor
DDC compound motor
#253📘 EE Pocket Reviewer RojasEasy
Which of the following motors has relatively wider range of speed control?
ASynchronous motor
BSlip ring induction motor
CSquirrel cage induction motor
DDC shunt motor
#254📘 EE Pocket Reviewer RojasEasy
What is the lubrication used in ball and roller bearings?
AGraphite
BWater
CGrease
DAir
#255📘 EE Pocket Reviewer RojasEasy
During rheostatic braking of a dc motor, which of the following is true?
AIt works as a dc generator
BThe direction of its field current is reversed
CIts field is disconnected from the supply
DIts armature is reverse connected
#256📘 EE Pocket Reviewer RojasEasy
Basically all electric motors operate based on which of the following principles?
AMagnetism
BConduction
CInduction
DCommutation
#257📘 EE Pocket Reviewer RojasEasy
What is the cause of hot bearings in a dc motor?
ALack of lubricant
BLoose coupling
CPoor air ventilation
DAll of these
#258📘 EE Pocket Reviewer RojasEasy
A reciprocating pump which is required to start under load, which motor is more preferred?
ARepulsion motor
BDouble-cage squirrel cage induction motor
CSquirrel-cage induction motor
DSynchronous motor
#259📘 EE Pocket Reviewer RojasEasy
For blowers, which of the following motors is preferred?
ADC series motors
BDC shunt motors
CSquirrel cage induction motors
DWound rotor induction motors
#260📘 EE Pocket Reviewer RojasEasy
Which of the following motors is preferred when quick speed reversal is the main consideration?
ADC motors
BSynchronous motors
CSquirrel cage induction motors
DWound rotor induction motors

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