Recent questions tagged motor

asked May 22, 2020 by anonymous

Explain the necessity of starter for D.C. motor. State various types of D.C. motor starter.

Last answer: Necessity of Starter for D.C. Motor: Armature current is given by equation Ia = (V−Eb)/Ra i) If the motor is at standstill or rest, back emf Eb is zero (as Eb= ZNP/(60A), at start speed N ... . Types of D.C. motor starters: i) Two point starter ii)Three point starter iii) Four point starter

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80 views 1 answer

asked May 22, 2020 by anonymous

State at least one function and the material used for the following parts of DC Motor.

Last answer: Part Function Material Yoke -Provides mechanical support for poles -Acts as protecting cover for machine -Provides path for magnetic flux Cast Iron OR Cast Steel Field Winding - ... Pole core Provides mechanical support to field winding. Cast Iron OR Cast Steel

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31 views 1 answer

asked May 22, 2020 by anonymous

Explain the working principle of induction motor.

Last answer: Working principle of induction motor: * When the motor is excited with three-phase supply, three-phase stator winding carries three-phase currents & produces a rotating magnetic field of constant magnitude and ... , which tend to move the rotor in the same direction as the rotating magnetic field.

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39 views 1 answer

asked May 7, 2020 by anonymous

State the insulating materials used in motor. Write temperature class and withstand temperature ranges for them.

Last answer: The insulating materials used in motor are as belows: 1. Cotton, 2. Silk, or paper, 3. Press board, 4. Resins 5. PVC 6. Cellulose-Fiber, 7. Enameled coating, etc ... Over 180° Mica, porcelain, ceramics, glass quartz, asbestos, treated glass fiber or treated asbestos. etc.

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63 views 1 answer

asked May 7, 2020 by anonymous

List different starting methods of three phase synchronous motor. Explain any one of them.

Last answer: Different Starting Methods of Three Phase Synchronous Motor: As synchronous motor is not self starting, different methods of starting are as follows: 1) By using an Induction (Pony) motor 2) ... . The rotor gets pulled into synchronism and starts running at constant speed as a synchronous motor.

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62 views 1 answer

asked May 7, 2020 by anonymous

Draw and explain V and inverted V curves for synchronous motor.

Last answer: V curves' and inverted V curves' for Synchronous Motor: V curve: V curve is a plot of the stator current versus field current for different constant loads. The graph is plotted ... Vcurves of synchronous motor. The highest point on each of these curves indicates unity power factor.

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155 views 1 answer

asked May 7, 2020 by anonymous

State the modification to be done in dc series motor to work satisfactorily as ac series motor. State applications of ac series motor.

Last answer: Modifications are necessary in a dc series motor so that it operates satisfactorily on ac supply. The modifications are as follows: 1) AC series motor is built with a few field turns as ... and grinders 5) High speed vacuum cleaners 6) Sewing machines 7) Food processors 8) Drilling machine

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77 views 1 answer

asked May 7, 2020 by anonymous

Explain the activities carried out during weekly maintenance of 3 ph. Induction motor.

Last answer: Activities Carried out During Weekly Maintenance of 3 ph. Induction Motor: 1) Check belt tension. In cases where this is excessive it should immediately be reduces and in the case of sleeve ... and cooled by oil mist systems its important to check the oil mist flow paths/pressure components.

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75 views 1 answer

asked May 7, 2020 by anonymous

Describe with neat sketch working of hysteresis motor.

Last answer: Working: When stator is energized with single phase ac supply, rotating magnetic field is produced because of starting (auxiliary) and main windings, which remain in circuit permanently. The ... the principle of magnetic locking this motor either rotates at synchronous speed or not at all.

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119 views 1 answer

asked May 7, 2020 by anonymous

List applications of stepper motor.

Last answer: Applications of Stepper Motor: 1) Computer controlled systems 2) Numerical control of machine tools 3) Tape drives 4) Floppy disc drives 5) Computer printers 6) X-Y plotters 7) ... ) Extruders 21) Engravers 22) Analytical and Medical instruments 23) Embroidery Machines 24) Packaging Machines

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62 views 1 answer

asked May 7, 2020 by anonymous

List different torques in synchronous motor.

Last answer: Different Torques in Synchronous Motor: 1) Starting torque 2) Running torque 3) Pull-in torque 4) Pull-out torque

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49 views 1 answer

asked May 7, 2020 by anonymous

State suitable single phase motor for following applications: (i) Table fan (ii) Mixers and Grinders

Last answer: Application Suitable Single Phase Motor Table Fan 1) Capacitor split phase motor 2) Capacitor start capacitor run motor Mixers and Grinders 1) Universal motor 2) A.C. Series motor

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51 views 1 answer

asked May 7, 2020 by anonymous

State the function of following parts in Induction motor. (i) Stator (ii) Slip rings

Last answer: Name of part Function Stator 1) Stator frame supports the core, terminal box and protects the inner parts. 2) Stator core houses stator winding. 3) Stator winding ... ) Provides facility to connect external resistance to rotor circuit through brushes for starting and control.

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50 views 1 answer

asked May 3, 2020 by anonymous

List the energy conservation technique in induction motor.

Last answer: Following are the list of energy conservation techniques in electrical motors: 1) Reduction in iron losses by using low loss silicon steel core material laminated to thinner dimension. 2) Using bigger length ... at light load. 13) By rewinding in induction motor 14) By motor survey

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68 views 1 answer

asked Apr 27, 2020 by anonymous

With a neat sketch give the working of shaded pole induction motor.

Last answer: Explanation: It has squirrel cage rotor and salient pole stator. The stator poles are shaded partially by short circuited conductor band to create the phase difference between the fluxes emerging from shaded ... rotating magnetic field in the air-gap and torque is exerted on the squirrel cage rotor.

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109 views 2 answers

asked Apr 27, 2020 by anonymous

List the main parts of D.C. motor

Last answer: Main parts of D.C. motor and their functions: Part Functions Yoke i) Provides mechanical support for poles. ii) Acts as protecting cover for machine. iii) Carries magnetic flux. ... a fixed physical position relative to the stator. Shaft Used to transfer mechanical power

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67 views 1 answer

asked Apr 27, 2020 by anonymous

List different types of stepper motor. State one application of stepper motor.

Last answer: Types of stepper motor : (i)Variable - reluctance motor (ii) Permanent- magnet motors (iii) Hybrid motors. Applications of stepper motor : In robotics, In CNC machines, In computers, printers, ... In Watches, In biomedical applications such as X-ray machines, CT scan, In Process control systems.

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44 views 1 answer

asked Apr 27, 2020 by anonymous

Write two applications of D.C. series motor.

Last answer: The applications of D.C. series motor: 1. Cranes 2. Hoists 3. Trolley and cars 4. Conveyors 5. For traction work i.e. electric locomotives 6. Elevator 7. Air compressor

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58 views 1 answer

asked Apr 27, 2020 by anonymous

State the principle of operation of d.c. motor.

Last answer: When a current carrying conductor is placed in a magnetic field, the conductor experiences the force. The magnitude of force is given by F = BIL newton where F – Force B – maximum flux density I – Current L – Length of conductor

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78 views 1 answer

asked Apr 24, 2020 by anonymous

DC motor gross torque example

Last answer: .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

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110 views 2 answers

asked Apr 23, 2020 by anonymous

DC shunt motor

Last answer: .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

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108 views 2 answers

asked Apr 22, 2020 by anonymous

DC motor brake test numerical

Last answer: .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

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49 views 2 answers

asked Apr 21, 2020 by anonymous

Brake test on DC series motor

Last answer: .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

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155 views 2 answers

asked Apr 16, 2020 by anonymous

Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor

Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor.

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84 views 0 answers

asked Apr 16, 2020 by anonymous

Explain the need and steps to conduct the reduced voltage running up test on the three phase induction motor.

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57 views 0 answers

asked Oct 13, 2019 by anonymous

Speed control of the motor using TRIAC

Last answer: Speed control of the motor using TRIAC: This basic phase triggering circuit uses the triac in series with the motor across an AC sinusoidal supply. The variable resistor, VR1 is used ... meaning that it may not trigger at the exact same point for each positive and negative half cycle.

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208 views 1 answer

asked Sep 2, 2019 by anonymous

Why is a capacitor used in a single phase motor and not in three phase motor ?

Last answer: In 1-phase induction motor capacitor work is generate the auxiliary winding current than excite the main winding to rotor starts rotate. After rotor start rotating about 75% of their speed than auxiliary ... emf to start the motor.so,in 3-phase induction motor is self start induction motor.

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127 views 6 answers

asked Aug 28, 2019 by anonymous

What is the difference between Generator and Motor?

Last answer: If a rotating machine delivers a power as output it is called generator. If power required to rotate a machine it is called motor.

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97 views 3 answers

asked Aug 25, 2019 by anonymous

If field current is decreased in shunt dc motor, the speed of the motor

If field current is decreased in shunt dc motor, the speed of the motor (a) remains same. (b) increases. (c) decreases. (d) none of the above.

Last answer: increases

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1.4k views 4 answers

asked Aug 21, 2019 by anonymous

working principle of single phase motor

Last answer: The Stator of single phase induction motor houses two windings 1. Main (Running) winding 2. Auxiliary (Starting ) winding Rotor of single phase induction motor is ... with starting winding or a capacitor may be permanently connected in series with Auxiliary (Starting ) winding.

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93 views 1 answer

asked Aug 18, 2019 by anonymous

What will happen if the induction motor runs at synchronous speed ?

Last answer: Since there is always slip present in rotor it cannot run at synchronous speed no current will be developed hence no torque will developed

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68 views 3 answers

asked Aug 18, 2019 by anonymous

What would happen if a DC motor was supplied with AC ?

Last answer: With three phase induction motor, humming and not rotate, but if single phase universal motor like air blower, home mixture, motor run on constant speed..speed variation not possible...

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91 views 2 answers

asked Aug 17, 2019 by anonymous

State working principle and applications of servo motor.

Last answer: Working Principle of Servo Motor: Basically servo motor is made up of DC motor, which is controlled by a potentiometer and some gears. Its angle of rotation is controlled by the duration of ... Packaging 6) Woodworking 7) Textiles 8) Printing 9) Robotics 10) Portable drilling 11)Process control

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41 views 1 answer

asked Aug 17, 2019 by anonymous

State working principle of universal motor with the help of diagram.

Last answer: Working Principle of Universal motor : It is modified DC series motor which can work on AC as well as DC supply. According to basic motor principle, whenever a current carrying conductor is placed in magnetic ... They have nearly same operating characteristic for both AC and DC supply.

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56 views 1 answer

asked Aug 17, 2019 by anonymous

applications of each: i) Universal motor ii) Stepper motor.

Last answer: i) Applications of Universal motor: 1) portable drills 2) hair dryers 3) grinders 4) mixers 5) table-fans 6) blowers 7) polishers 8) Kitchen appliances ii) Applications of Stepper motor ... 7) robotics 8) CNC machine 9) Control systems 10) Biomedical applications 10) XY recorder 11) plotters

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52 views 1 answer

asked Aug 17, 2019 by anonymous

Define Slip of Induction Motor.

Last answer: Slip: It is the ratio of relative speed of rotor (difference between synchronous speed and rotor speed) to the synchronous speed of rotating magnetic field. Slip = (NS – N) / NS where , NS = synchronous speed, N = speed of rotor

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32 views 1 answer

asked Jul 30, 2019 by anonymous

Explain the working of a single phase capacitor start induction motor.

Last answer: Single phase capacitor start induction motor https://youtu.be/31lvvzU5Puc

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144 views 2 answers

asked Jul 30, 2019 by anonymous

State the function of following parts of DC motor : i) Yoke ii) Poles iii) Field winding iv) Commutator.

Last answer: Function : i) Yoke: The yoke serves the following two purposes. i) It supports the other components such as poles and provides mechanical protection for whole machine. ii) It forms a part of ... one pole to another and thus to help the motor to develop a continuous and unidirectional torque

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92 views 1 answer

asked Jul 30, 2019 by anonymous

State any four advantages of three phase induction motor.

Last answer: Advantages of three phase induction motor https://youtu.be/27OIOCKN05U

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100 views 2 answers

asked Jul 27, 2019 by anonymous

State any four applications of DC shunt motor.

Last answer: Applications of DC shunt motor: 1) Lathe machines 2) drilling machines 3) milling machines 4) Printing machinery 5) Paper industry 6) centrifugal and reciprocating pumps 7) blowers 8)fans

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79 views 2 answers

asked Jul 26, 2019 by anonymous

State two applications of 1) Shaded pole motor 2) Universal motor

Last answer: (i)Applications of Shaded pole motor: 1. Small fans 2. Toy motors 3. Hair dryers 4. Ventilators 5. Electric clocks 6. Record players 7. Motorized valves 8. Gramophones 9. Photocopying ... 5. Portable Drilling Machines 6. Electric Shavers 7. Mechanical computing Machines 8. Machine Tools etc.

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90 views 1 answer

asked Jul 20, 2019 by anonymous

Draw and explain working of universal motor. Give two applications of universal motor.

Last answer: Figure of Universal motor: Operation of universal motor on A.C. and D.C. supply: *A universal motor works on either DC or single phase AC supply. When the universal motor is ... , regardless of AC or DC supply, universal motor works on the same principle that DC series motor works.

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247 views 4 answers

asked Jul 5, 2019 by anonymous

Why does the speed of a DC shunt motor decrease as the load increases?

Last answer: Because if the load is increasing then the torque must also be increase. If not then the speed of motor will decrease.

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2.5k views 1 answer

asked Sep 22, 2018 by anonymous

Explain energy conservation technique in induction motor by minimizing idle and redundant running of motor.

Last answer: Energy conservation technique in induction motor by minimizing idle and redundant running of motor: 1) Loss of energy as the no load power drawn is approximately about 12% to 16% of rated ... to unnecessary line losses. 4) Reduction in overall system energy efficiency over period of time.

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375 views 1 answer

asked Sep 22, 2018 by anonymous

State the need of energy conservation in electrical motor.

Last answer: Need of energy conservation in Electrical motors: 1. Induction motors are used as electrical drives in industrial, commercial and residential sectors. 2. Considering all industrial applications, 70% of ... system. 8. To adopt advanced technology in design and to use better quality materials.

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92 views 2 answers

asked Sep 22, 2018 by anonymous

Describe the following energy conservation methods of electrical motor. i) By motor survey ii) By matching loads with motor rating

Last answer: Energy conservation methods of electrical motor: 1) By Motor Survey: Large industries have a massive population of LT motors. Load survey of LT motors can be taken-up methodically to ... -speed motors, eddy-current couplings, fluid couplings, and solid-state electronic variable speed drives.

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172 views 1 answer

asked Sep 22, 2018 by anonymous

State and explain any four factors governing selection of induction motor.

Last answer: The factors governing the selection of Induction motor: 1) Load torque required at normal speed matches with available torque of motor. 2) Break down torque or pull out torque or maximum torque ... If selecting energy efficient motor the cost benefit analysis over the long run must be worked out.

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2.6k views 1 answer

asked Sep 22, 2018 by anonymous

Explain energy conservation technique “by improving power quality” for induction motor.

Last answer: Energy conservation method in induction motor by improving power quality: Electrical energy can be conserved by improving the power quality. It can be achieved by avoiding voltage unbalance, maintaining ... losses can be minimized by using harmonic filter thus reducing the harmonics in the system.

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2.9k views 2 answers

asked Sep 20, 2018 by anonymous

Split phase induction motor

Last answer: Split phase induction motor : There are two windings used in split phase induction motor. It is a type of single-phase induction motor. There are two winding one is called main winding and ... motor have low starting torque it is used for small fans, blowers, centrifugal pumps, grinders etc.

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178 views 1 answer

asked Sep 18, 2018 by anonymous

State starters used for i) 3-Ph squirrel cage induction motor (3HP) ii) D.C. motor

Last answer: Name the starters used for following motors : i) 3 H.P. 3-Ph squirrel cage I.M: i) DOL starter OR ii) Star-Delta Starter OR ii) Auto transformer starter OR iii) Soft start starter. ii) D.C Shunt Motor : 1) Armature resistance starter (Three Point Starter) OR 2) Four Point Starter

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118 views 1 answer