speed control methods of three phase induction motor?
Last Answer : Speed control of three phase induction motor
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Aug 9, 2017
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anonymous
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Armature control of DC motor
Last Answer : Armature control of DC motor
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Aug 9, 2017
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anonymous

Field control of DC motor
Last Answer : Field control of DC motor
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Aug 9, 2017
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anonymous

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque (1) Decreases (2) Increases (3) Remains constant (4) None of the above
Last Answer : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases
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May 1, 2018
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anonymous

Last Answer : Series motor has the poorest speed control.
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103 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : Speed control of a universal motor is achieved by varying field flux with tapped field windings, connecting rheostat in series, applying variable voltage by means of silicon controlled rectifier, applying variable voltage by means of variable auto-transformer.
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1 answer
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Mar 20, 2018
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anonymous

Last Answer : The speed control of universal motor used for sewing machines is by varying the resistance.
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105 views
1 answer
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Mar 20, 2018
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anonymous

A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be
Last Answer : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be 474 V
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1 answer
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May 8, 2018
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anonymous

Last Answer : The armature voltage control of D.C. motor provides constant torque drive.
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92 views
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Mar 20, 2018
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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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Oct 13, 2019
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anonymous

The speed of a D.C. motor can be controlled by varying 1. Its flux per pole 2. Resistance of armature circuit 3. Applied voltage 4. All of the above
Last Answer : The speed of a D.C. motor can be controlled by varying 1. Its flux per pole 2. Resistance of armature circuit 3. Applied voltage 4. All of the above
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390 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : The speed of a D.C. shunt motor can be increased by increasing the resistance in field circuit.
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134 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : As the load is increased the speed of D.C. shunt motor will reduce slightly.
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1 answer
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Mar 20, 2018
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anonymous

Last Answer : The speed of a D.C. series motor is inversely proportional to the armature current.
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114 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : In a D.C. shunt motor, speed is independent of armature current.
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87 views
1 answer
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Mar 20, 2018
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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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2.7k views
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Jul 5, 2019
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anonymous

The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ (A) directly proportional to α and Φ (B) ... proportional to α and inversely proportional to Φ (D) directly proportional to Φ and inversely proportional to α
Last Answer : The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ directly proportional to α and inversely proportional to Φ
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150 views
1 answer
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Apr 28, 2018
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anonymous

Last Answer : If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will increase.
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201 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : Usually wide and sensitive speed control is desired in case of colliery winders.
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141 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : Speed control by Ward Leonard method gives uniform speed variation in both directions.
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129 views
1 answer
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Mar 20, 2018
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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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May 7, 2020
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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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1 answer
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Sep 22, 2018
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anonymous

The fall in speed of a dc generator due to increase in load can be corrected by (1) cooling the armature.. (2) increasing the excitation. (3) reducing the load voltage. (4) increasing the input to the prime mover
Last Answer : It can be corrected by increasing the input to the prime mover.
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355 views
2 answers
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May 1, 2018
by
anonymous

Describe the reason of using dc series motor for electric trains.
Last Answer : Electric trains require an inverse torque speed characteristics for proper operation. That is a higher torque is required at start (when speed is nil or low) and as the train picks up ... torque - speed characteristics of DC series motors match, these motors are suitable for electric trains
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Sep 18, 2018
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anonymous

A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is
Last Answer : A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is 36 Ohm
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May 3, 2018
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anonymous

In a 2 kW, 200 V, 1000 rpm. DC series motor the torque at full load was found to be 0.3 N -m. The torque at half full load in N -m is :
Last Answer : In a 2 kW, 200 V, 1000 rpm. DC series motor the torque at full load was found to be 0.3 N -m. The torque at half full load in N -m is : 0.075
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109 views
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Apr 29, 2018
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anonymous

The function of a brush and commutator arrangement in a dc motor is to (1) produce unidirectional torque (2) produce unidirectional current in the armature (3) help in changing the direction of rotation of the armature (4) reduce sparking
Last Answer : The function of a brush and commutator arrangement in a dc motor is to produce unidirectional torque
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1 answer
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Apr 29, 2018
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anonymous

What is the RPM of a DC motor?
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0 answers
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Mar 15, 2018
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anonymous

Last Answer : Induction motor is a AC motor it is also known as asynchronous motor .
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98 views
1 answer
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Sep 9, 2017
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anonymous

Separately Excited DC motor
Last Answer : Separately Excited DC motor
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356 views
2 answers
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Aug 9, 2017
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anonymous

Four Quadrant Operation Of DC Motor
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Aug 9, 2017
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anonymous
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The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min (A) 100 rpm (B) 200 rpm (C) 400 rpm (D) 800 rpm
Last Answer : The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min 200 rpm
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1 answer
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Apr 28, 2018
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anonymous

Last Answer : In variable speed motor a weaker commutating field is needed at low speed than at high speed.
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1 answer
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Mar 20, 2018
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anonymous

Last Answer : For the same H.P. rating and full load speed, following motor has poor starting torque differentially compounded.
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164 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : The speed of a universal motor is usually reduced by using gearing.
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1 answer
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Mar 20, 2018
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anonymous

Last Answer : In case of a reluctance motor, when the load is increased so that it cannot maintain synchronous speed the motor will run as induction motor.
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1 answer
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Mar 20, 2018
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anonymous
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Last Answer : Centrifugal switch disconnects the auxiliary winding of the motor at about 70 to 80 percent of synchronous speed.
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1 answer
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Mar 20, 2018
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anonymous

Last Answer : The speed/load characteristics of a universal motor is same as that of D.C. series motor.
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175 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : Speed torque characteristic of a repulsion induction motor is similar to that of a D.C. compound motor.
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164 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in damage to the starting winding.
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129 views
1 answer
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Mar 20, 2018
by
anonymous

Why the speed of synchronous motor is constant?
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67 views
0 answers
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Mar 15, 2018
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anonymous

Last Answer : In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will remain unchanged.
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228 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The speed of a D.C. shunt motor more than its full-load speed can be obtained by decreasing the field current.
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147 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : In Ward-Leonard control the lower limit of speed is imposed by residual magnetism of the generator.
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79 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : For constant torque drive armature voltage control speed control method is preferred.
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177 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : In case of D.C. shunt motors the speed is dependent on back e.m.f. only because flux is practically constant in D:C. shunt motors.
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250 views
1 answer
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Mar 20, 2018
by
anonymous
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Last Answer : When two D.C. series motors are connected in parallel, the resultant speed is normal speed.
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378 views
1 answer
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Mar 20, 2018
by
anonymous

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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2.8k views
4 answers
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Aug 25, 2019
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anonymous

MCQ on Motor Control Center
Last Answer : 1. MCC stands for ______ a. Motor Control Center b. Motor Control Cost c. Machine Components Center d. None of the above Answer : a. Motor Control Center 2. MCC contains _____ a. Fuse b. MCB c. ... a) Start the motor b) Accelerate the motor c) Decelerate the motor d) Stop the motor Answer : a
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1 answer

Last Answer : If a D.C. motor designed for 40°C ambient temperature is to be used for 50°C ambient temperature, then the motor is to be derated by a factor recommended by manufacturer and select the next higher H.P. motor.
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97 views
1 answer
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Mar 20, 2018
by
anonymous
