Easy DC Motors Questions – Electrical Engineering (Page 2)

#21📜 EE Pre-Board March 2018📘 PowerhouseEasy

In a shunt motor, what is the relative connection of the armature winding with respect to the field winding?

Aseries

Bparallel-series

Cseries-parallel

Dparallel

#22📜 EE Pre-Board March 2018📘 PowerhouseEasy

In a series motor, what is the connection of the field winding with respect to the armature?

Aseries

Bparallel

Cseries-parallel

Ddelta

#23📜 EE Pre-Board March 2018📘 PowerhouseEasy

Find the horsepower rating of a motor running at 1,500 rpm and developing a torque of 105 lb-ft.

A22

B28

C30

D36

#24📜 EE Pre-Board March 2018📘 PowerhouseEasy

When the motor runs on no load, then

ABack emf is almost equal to applied voltage

BBack emf will be greater than applied voltage

CBack emf will be less than applied voltage

DNone of these

#25📜 EE Pre-Board March 2018📘 PowerhouseEasy

A device that repeatedly reverses the polarity of a magnetic field in order to keep a dc motor rotating is known as

Aa solenoid

Ban armature coil

Ca commutator

Da field coil

#26📜 EE Pre-Board August 2018📘 PowerhouseEasy

If the field of a dc shunt motor is opened

Ait will continue to run at its rated speed

Bthe speed of the motor will become very high

CThe motor will stop

Dthe speed of the motor will decrease

#27📘 EE Pocket Reviewer RojasEasy

Which motor is used in electric shavers?

AShaded-pole motor

BHysteresis motor

CReluctance motor

DUniversal motor

#28📘 EE Pocket Reviewer RojasEasy

What is the purpose of the compensating windings in a series ac motor?

ATo compensate for decrease in field flux

BTo increase the torque capacity

CTo reduce the sparking at the brushes

DTo reduce effects of armature reaction

#29📘 EE Pocket Reviewer RojasEasy

Ward Leonard controlled DC drives are generally used in which of the following types of excavators?

ALight duty

BMedium duty

CHeavy duty

DAll of these

#30📘 EE Pocket Reviewer RojasEasy

Which of the following is true about a capacitor- start, capacitor-run induction motor?

AIt has no centrifugal switch

BIt has a noisy operation

CIt has a low power factor

DIt has a low efficiency

#31📘 EE Pocket Reviewer RojasEasy

Most single-phase motors have how many poles?

A2 poles

B6 poles

C4 poles

D8 poles

#32📘 EE Pocket Reviewer RojasEasy

Most of the troubles in single phase induction motors are traceable in which of the following?

ARotor bars

BMain winding

CStarting switch

DShaft bearings

#33📘 EE Pocket Reviewer RojasEasy

Single phase series motor can operate using what type of voltage?

AAC only

BDC only

CBoth AC and DC voltages

DAny type of voltages

#34📘 EE Pocket Reviewer RojasEasy

Which motor is generally employed in a washing machine?

AHysteresis motor

BShaded pole motor

CSeries ac motor

DResistance split phase motor

#35📘 EE Pocket Reviewer RojasEasy

Which of the following application a reluctance motor is preferred?

ASignalling and timing devices

BElectrical shavers

CLifts and hoists

DRefrigerators

#36📘 EE Pocket Reviewer RojasEasy

Which one is the least expensive fractional horsepower motor?

ASplit-phase motor

BShaded pole motor

CCapacitor start motor

DAC series motor

#37📘 EE Pocket Reviewer RojasEasy

For the same rating, which dc motor has the lowest starting torque?

AShunt motors

BSeries motors

CLong-shunt compound motors

DShort-shunt compound motors

#38📘 EE Pocket Reviewer RojasEasy

The shaft torque of dc motor is less than the armature torque due to this loss. Which one?

ACopper loss

BIron loss

CMechanical loss

DRotational loss

#39📘 EE Pocket Reviewer RojasEasy

Which of the following is the most common method used in controlling the speed of a dc motor?

AVary the supply voltage

BVary the field strength

CVary the number of field pole

DVary the armature circuit resistance

#40📘 EE Pocket Reviewer RojasEasy

What is the rotating part of a dc motor?

APole

BStator

CArmature

DCarbon brush

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