Three Phase Induction Motor Question & AnswersMarch 3, 2023 By Wat Electrical This article lists 75 Three Phase Induction Motor MCQs for engineering students. All the Three Phase Induction Motor Questions & Answers given below include a hint and a link wherever possible to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up on the fundamentals of the Three Phase Induction Motor.The three-phase induction motors are self-starting motors that run at a constant speed from zero to load. The frame, stator, stator winding, rotor winding, cooling fan, and bearings are the components of three phase induction motor. The stator is a stationary part of an induction motor that consists of a stator winding. The rotor in a three-phase induction is housed on the shaft of an induction motor. The stator current control and stator voltage control are the methods of speed control of an induction motor.The rotor in a three-phase induction motor has two ends one is called the non-driving end and another is called the driving end. Induction motors are widely used power drive that runs at a constant speed. The constant or fixed losses and variable losses are the losses that occur in three phase induction motor. The three-phase induction motors are simple to design, low cost requires minimum maintenance, and has high efficiency & good pf at full load. The squirrel cage induction motor and slip ring induction motors are the type of three-phase induction motors. 1). The armature of both synchronous and DC machines is an example of __________________ winding? Concentrated windings Distributed windings Closed windings Open windings None Hint2). Which one of the following windings is also known as Un bifurcated winding? Mush windings Whole coil windings Distributed windings Half coil windings None Hint3). The hemitropic winding is a type of winding comes under _______________ winding? Single layer winding Double winding Lap winding Wave winding None Hint4). The integral slot and fractional slot come under _______________ winding? Concentric winding Mush winding Lap winding Single layer winding None Hint5). Which one of the following motors always run with lagging power factor? Induction motor Synchronous motor Asynchronous motor All of the above None Hint6). The power range of single-phase squirrel cage motor is _______________? Up to 500 hp Up to 50 hp Up to 15 hp Up to 5 hp None Hint7). The direct-on-line, star delta are the starting methods of an ___________________ induction motor? Slip ring motor Single phase squirrel cage IM Three phase squirrel cage IM Split ring motor None Hint8). The figure shown below is a configuration of derive system for two phase ____________ motor? Two phase IM Single phase squirrel cage IM Three phase squirrel cage IM Split ring motor None Hint9). Which one of the following starting methods for induction motor is simple and inexpensive? Star delta Direct-on-line Soft start Variable frequency drive None Hint10). Which one of the following one controls the motor throughout its operation? Soft starter VFD Autotransformer Direct-on-line starter None Hint11). Which one of the following starting methods for an induction motor has advantage of reduced in rush current and voltage dip? Star delta Direct-on-line Soft start Variable frequency drive None Hint12). The smooth acceleration is an advantage of _________________ starting method of an IM? Primary resistance Wye delta Direct-on-line Part winding None Hint13). The load on the motor is a cause of _________________ losses? Stray load Load related Friction and windage Core None Hint14). Which one of the following is also known as mesh connection? Wye connection Soft starter connection Autotransformer connection Delta connection None Hint15). Which one of the following windings is also called double layer winding? Basket windings Whole coil windings Distributed windings Half coil windings None Hint16). Which one of the following brakes is classified based on drivers' ergonomics? Hand brakes Parking brakes Mechanical brakes Hydraulic brakes None Hint17). ________________ is a type of brake based on basis of actuating method? Foot brakes Hand brakes Hydraulic brakes Parking brakes None Hint18). The efficiency and power factor are high in ________________ induction motor? Three phases Single phase Split phase Permanent split capacitor None Hint19). The permanent single capacitor induction motor is a __________________ phase technique? Split Shaded pole Reluctance SRM None Hint20). Which one of the following is used only for motor start and stop control? Soft starter VFD Autotransformer Direct-on-line starter None HintThree Phase Induction Motor MCQ for Exams21). The power range of three-phase squirrel cage motor is _______________? Up to 500 hp Up to 50 hp Up to 15 hp Up to thousands of hp None Hint22). The smooth acceleration, reduced mechanical stress are the advantage of _______________ starting method? Star delta Direct-on-line Soft start Variable frequency drive None Hint23). What are the characteristics of brake fluid? Viscosity Boiling point Corrosion resistance All of the above None Hint24). The transient response is fast in ________________ induction motor? Scalar V/F control Vector control IM Both a and b None of the above None Hint25). What are the reasons of an insulation failure in winding burning? System disturbances Excessive load inertia Voltage spikes from VFDs All of the above None Hint26). Which one of the following brakes is classified based on location in the vehicle? Hand brakes Wheel mounted brakes Mechanical brakes Foot brakes None Hint27). Which one of the following is a type of brake based on application of braking effort? Band brakes Servo brakes Disc brakes Drum brakes None Hint28). What are the components of drum type brake system? Braking plate Brake drum Wheel cylinder All of the above None Hint29). The figure shown below is a ____________ phase induction motor? Two phase IM Single phase squirrel cage IM Three phase IM Split ring motor None Hint30). Which one of the following starters does not decreases the starting current? Star delta VFD Autotransformer Direct-on-line starter None Hint31). What are the advantages of three phase induction motor? Simple design Rugged construction Reliable operation All of the above None Hint32). Which class squirrel cage induction motor used for driving intermittent load? Class A squirrel cage Class B squirrel cage Class C squirrel cage Class D squirrel cage None Hint33). What is the standard form of DFIG? Doubly Fed Induction Generator Doubly First Induction Generator Doubly Fed Internal Generator Doubly Fed Integral Generator None Hint34). What are the methods of speed control of an induction motor? Stator current control Stator frequency control Stator voltage control All of the above None Hint35). _________________ are the parts of regenerative braking system? Alternator Inverter Convertor All of the above None Hint36). Which one of the following brakes is classified based on purpose served? Main operational brakes Wheel mounted brakes Transmission mounted brakes Foot, hand brakes None Hint37). The internal expanding brakes classified based on ___________________? Action of brake shoe Based on combinations Based on speciality Based on construction None Hint38). Which one of the following is a type of brake based on construction? Manual brakes Servo brakes Power brakes Drum brakes None Hint39). The figure shown below is a circuit diagram of phase ____________ motor? Two phase IM Capacitor stator Three phase IM Split phase IM None Hint40). What is the standard form of ABS? Anti Braking System Analog Braking System AC Braking System Anti Board System None HintThree Phase Induction Motor MCQ for Quiz41). The starting torque is low in ___________________ starting method of an IM? Star delta Autotransformer Both a and b Direct-on-line None Hint42). The current flowing through the stator and rotor winding are _______________ losses? Stray load losses Stator copper and rotor copper Friction and windage losses Core losses None Hint43). What is the standard form of DFIM? Doubly Fed Induction Machine Doubly First Induction Machine Doubly Fed Internal Machine Doubly Fed Integral Machine None Hint44). The production cost and torque to current ratio is lower in ________________? PMSM SRM Induction motor None of the above None Hint45). What are the reasons of a frame related mechanical failure? Base plate distortion Foundation Deterioration Foundation size and design All of the above None Hint46). The starting current is very high in ___________________ starting method of an IM? Star delta Direct-on-line Soft start Series reactor None Hint47). The fluctuation in the magnetic field is a cause of _______________ losses? Stray load losses Load related losses Friction and windage losses Core losses None Hint48). What are the disadvantages of delta connection? More torque Efficient Low voltage connection All of the above None Hint49). The figure shown below is a circuit diagram of phase ____________ motor? Two phase IM Capacitor stator PCM motor Split phase IM None Hint50). The primary and secondary windings of a transformer is an example of ________________ winding? Concentrated windings Distributed windings Closed windings Open windings None Hint51). What are the reasons of winding burning? Air gap fault Loose connections Electrical vibrations All of the above None Hint52). The movement of the rotor and air resistance is a cause of _______________ losses? Stray load losses Load related losses Friction and windage losses Core losses None Hint53). The rotor copper loss comes under _______________ losses? Variable Fixed Rotor copper Stator copper None Hint54). What are the advantages of delta connection? More torque Efficient Simple motor design All of the above None Hint55). What are the reasons of a bearing failure in winding burning? Vibration High ambient Fatigue All of the above None Hint56). Which class squirrel cage induction motor used for compressor? Class A squirrel cage induction motor Class B squirrel cage induction motor Class C squirrel cage induction motor Class D squirrel cage induction motor None HintRead more about Induction Motor57). The reduced in rush current, voltage dip and low cost are the advantages of _____________ starting method? Star delta Direct-on-line Soft start Series reactor None Hint58). The energy efficiency is high in ___________________ starting method of an IM? VFD Primary resistance Direct-on-line Both b and c None Hint59). The figure shown below is a circuit diagram of phase ____________ motor? Two value capacitor motor Shaded pole motor PCM motor Split phase motor None Hint60). Which one of the following windings used for AC commutator machines and DC machines? Concentrated windings Distributed windings Closed windings Open windings None HintThree Phase Induction Motor MCQ for Interviews61). What are the reasons of a rotor related mechanical failure? Bad mechanical fits Shaft deformation Rotor deflection All of the above None Hint62). Which class squirrel cage induction motor used for constant speed drive such as pump, and blower? Class A squirrel cage induction motor Class B squirrel cage induction motor Class C squirrel cage induction motor Class D squirrel cage induction motor None Hint63). The precise speed control and energy saving are the advantages of ______________ starting method? Star delta Direct-on-line Soft start Variable frequency drive None Hint64). The mechanical stress is high in ___________________ starting method of an IM? VFD Primary resistance Both a and b Direct-on-line None Hint65). The interaction between stator and rotor is a cause of _________________ losses? Stray load Load related Friction and windage Core None Hint66). Which one of the following is also known as star connection? Wye connection Soft starter connection Autotransformer connection Delta connection None Hint67). The stator iron loss comes under _______________ losses? Variable Fixed Rotor copper Stator copper None Hint68). The figure shown below is a circuit diagram of ____________ motor? Two value capacitor motor Shaded pole motor PCM motor Split phase motor None Hint69). The constant power mode of operation is average in _______________ motor? SRM PMSM Induction motor All of the above None Hint70). Which one of the following windings used for AC machines? Concentrated windings Distributed windings Closed windings Open windings None Hint71). What are the reasons of a shaft related mechanical failure? Mounting breakage Shaft alignment Wrong coupling type All of the above None Hint72). Which one of the following windings is also known as half coil winding? Basket windings Whole coil windings Distributed windings Mush windings None Hint73). Which class squirrel cage induction motor used for fan, pump load, etc where torque is low at start? Class A squirrel cage induction motor Class B squirrel cage induction motor Class C squirrel cage induction motor Class D squirrel cage induction motor None Hint74). Which one of the following motors can be run under a wide range of of both leading and lagging? Induction motor Synchronous motor Asynchronous motor All of the above None Hint75). Which one of the following windings is also known as bifurcated winding? Mush windings Whole coil windings Distributed windings Half coil windings None HintFor More MCQsCapacitor Start Capacitor Run Motor Question & AnswersInduction Motor Question & AnswersReluctance Motor Question & AnswersSwitched Reluctance Motor Question & AnswersDC Motor Question & AnswersSynchronous Motor Question & AnswersSingle Phase Induction Motor Question & AnswersPoly Phase Induction Motor Question & Answers Time's up
