Electrical Engineering · Question Bank

DC Motors

285 questions · page 14 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
#261📘 EE Pocket Reviewer RojasEasy
Single-phase synchronous motors are used in teleprinters, clocks and all kinds of timing devices due to which of the following requirement?
ALow starting torque
BHigh power factor
CConstant speed
DOverload capacity
#262📘 EE Pocket Reviewer RojasEasy
Which of the following applications need frequent starting and stopping of electric motors?
APaper mills
BGrinding mills
CAir-conditioners
DLifts and hoists
#263📘 EE Pocket Reviewer RojasEasy
Which of the following motors has the least range of speed control?
ASlip ring induction motor
BSynchronous motor
CDC shunt motor
DSchrage motor
#264📘 EE Pocket Reviewer RojasEasy
What will be the effect of low voltage on the magnetic controller of a motor?
AIt will gum up
BIt will chatter
CIt will cause contacts to overheat
DAll of these
#265📘 EE Pocket Reviewer RojasEasy
Which of the following is the lubrication used for most of the gearmotors?
AOil
BGrease
CTalc
DBoth A and B
#266📘 EE Pocket Reviewer RojasEasy
What is the load cycle for a motor driving a power press?
AVariable load
BContinuous load
CContinuous but periodic load
DIntermittent and variable load
#267📘 EE Pocket Reviewer RojasEasy
Which of the following is not one of the senses commonly used by service technicians?
ASight
BHearing
CSmell
DTaste
#268📘 EE Pocket Reviewer RojasEasy
By changing the position of its brushes, the speed of this motor can be varied. Which one?
ASlip ring motor
BSchrage motor
CInduction motor
DRepulsion motor
#269📘 EE Pocket Reviewer RojasEasy
Which of the following motors are best suited for the rolling mills?
ASingle-phase motors
BSquirrel-cage induction motors
CSlip ring induction motors
DDC motors
#270📘 EE Pocket Reviewer RojasEasy
Which part of a motor needs maximum attention for maintenance?
AStator winding
BRotor winding
CBearing
DFrame
#271📘 EE Pocket Reviewer RojasEasy
Which of the following bearings should be oiled regularly?
ASleeve bearing
BBall bearing
CBoth A and B
DNone of these
#272📘 EE Pocket Reviewer RojasEasy
Which one is another name for a magnetic starter?
AManual switch
BContactor
CMechanical starter
DMagnetic control
#273📘 EE Pocket Reviewer RojasEasy
During regenerative braking of electric motors, which of the following statements is true?
AThey are disconnected from the supply
BThey are reverse connected to the supply
CThey are made to run as generators
DThey are made to stop
#274📘 EE Pocket Reviewer RojasEasy
Which of the following motors is not a self-starting motor?
ASynchronous motor
BDC compound motor
CSquirrel cage induction motor
DWound rotor induction motor
#275📘 EE Pocket Reviewer RojasEasy
Which type of bearings is used to support the rotor of a motor?
ABush
BNeedle
CBall or roller
DThrust
#276📘 EE Pocket Reviewer RojasEasy
For crane travel, which of the following motors are normally used?
AAC slip ring motor
BSynchronous motor
CDC differentially compound motor
DWard-Leonard controlled DC shunt motor
#277📘 EE Pocket Reviewer RojasEasy
Which one is considered the simplest form of a motor controller?
AMagnetic switch
BToggle switch
CDrum switch
DRelay
#278📘 EE Pocket Reviewer RojasEasy
Which of the following machines has heavy fluctuation of load?
APlaner
BLathe
CPrinting machine
DPunching machine
#279📘 EE Pocket Reviewer RojasEasy
Which of the following motors is preferred for the boom hoist of a traveling crane?
ASingle-phase motor
BSynchronous motor
CAC slip ring motor
DWard-Leonard controlled DC shunt motor
#280📘 EE Pocket Reviewer RojasEasy
Which of the following motors has series characteristics?
AShaded pole motors
BRepulsion motors
CCapacitor start motors
DAll of these

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