100 Important Industrial Drives MCQ Question & Answer | PDF Free Download
1.The starting torque of a DC motor is independent of which of the following?
- AFlux
- BArmature current
- CFlux and armature current
- DSpeed
2.Rotor of a motor is usually supported on ____________ bearings.
- ABall or roller
- BNeedle
- CBush
- DThrust
3.For which of the following applications DC motors are still preferred?
- AHigh efficiency operation
- BReversibility
- CVariable speed drive
- DHigh starting torque
4.In a paper mill where constant speed is required
- ASynchronous motors are preferred
- BAC motors are preferred
- CIndividual drive is preferred
- DGroup drive is preferred
5.A reluctance motor _____________
- AIs provided with slip rings
- BRequires starting gear
- CHas high cost
- DIs compact
6.The size of an excavator is usually expressed in terms of
- A?crowd? motion
- BAngle of swing
- CCubic metres
- DTravel in metres
7.For blowers which of the following motors is preferred?
- ADC series motor
- BDC shunt motor
- CSquirrel cage induction motor
- DWound rotor induction motor
8.Belted slip ring induction motor is almost invariably used for
- AWater pumps
- BJaw crushers
- CCentrifugal blowers
- DNone of the above
9.Which of the following is essentially needed while selecting a motor?
- APully
- BStarter
- CFoundation pedal
- DBearings
10.Reluctance motor is a ___________
- AVariable torque motor
- BLow torque variable speed motor
- CSelf-starting type synchronous motor
- DLow noise, slow speed motor
11.______________ method of starting a three phase induction motor needs six terminals.
- AStar-delta
- BResistance starting
- CAuto-transformer
- DNone of the above
12.In ___________ method of staring 3-phase induction motors the starting voltage is not reduced.
- AAuto-transformer
- BStar-delta
- CSlip ring
- DAny of the above
13.In jaw crushers a motor has to often start against ____________ load.
- AHeavy
- BMedium
- CNormal
- DLow
14.For a motor-generator set which of the following motors will be preferred?
- ASynchronous motor
- BSlip ring induction motor
- CPole changing induction motor
- DSquirrel cage induction motor
15.Which of the following motors is usually preferred for kiln drives?
- ACascade controlled AC motor
- BSlip ring induction motor
- CThree phase shunt wound commutator motor
- DAny of the above
16.Heat control switches are used in _____________
- ATransformers
- BCooling ranges
- C3-phase induction motors
- DSingle phase
17.____________ has relatively wider range of speed control.
- ASynchronous motor
- BShip ring induction motor
- CSquirrel cage induction motor
- DDC shunt motor
18.In squirrel cage induction motors which of the following methods of starting cannot be used?
- AResistance in rotor circuit
- BResistance in stator circuit
- CAuto-transformer starting
- DStat-delta starting
19.In which of the following applications the load on motor changes in cyclic order?
- AElectric shovels
- BCranes
- CRolling mills
- DAll of the above
20.Flame proof motors are used in
- APaper mills
- BSteel mills
- CMoist atmospheres
- DExplosive atmospheres