What are the speed control methods of dc motor?
Last Answer : Field control of DC motor Armature control of DC motor
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Dec 16, 2017
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anonymous

Armature control of DC motor
Last Answer : Armature control of DC motor
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162 views
2 answers
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Aug 9, 2017
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anonymous

Last Answer : If the field of a D.C. shunt motor gets opened while motor is running the motor will attain dangerously high speed.
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1 answer
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Mar 20, 2018
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anonymous

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

Last Answer : If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens this will make armature to take heavy current, possibly burning it.
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158 views
1 answer
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Mar 20, 2018
by
anonymous

From which material field coils of DC generator are made of?
Last Answer : Field coils of DC generator are usually made of copper.
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118 views
1 answer
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Mar 3, 2018
by
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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1 answer
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Mar 20, 2018
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anonymous
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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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104 views
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
by
anonymous

speed control methods of three phase induction motor?
Last Answer : Speed control of three phase induction motor
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376 views
2 answers
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Aug 9, 2017
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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142 views
1 answer
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Sep 18, 2018
by
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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May 8, 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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343 views
1 answer
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May 3, 2018
by
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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112 views
1 answer
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Apr 29, 2018
by
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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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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2 answers
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Aug 9, 2017
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anonymous

Four Quadrant Operation Of DC Motor
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0 answers
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Aug 9, 2017
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anonymous

Last Answer : In a shaded pole single-phase motor, the revolving field is produced by the use of shading coils.
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207 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will stop.
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258 views
1 answer
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Mar 20, 2018
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anonymous

An electric motor in which both stator field and rotor rotates with same speed is called?
Last Answer : An electric motor in which both stator field and rotor rotates with same speed is called synchronous motor.
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183 views
1 answer
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Mar 18, 2018
by
anonymous

If the field of synchronous motor is under excited, power factor will be?
Last Answer : If the field of synchronous motor is under excited, power factor will be lagging.
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499 views
1 answer
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Mar 18, 2018
by
anonymous

Last Answer : In a differentially compounded D.C. motor, if shunt field suddenly opens the motor will first stop and then run in opposite direction as series motor.
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94 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses.
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123 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
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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593 views
1 answer
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Jul 30, 2019
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anonymous

Last Answer : Flashing the field of D.C. generator means creating residual magnetism by a D.C. source.
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96 views
1 answer
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Mar 21, 2018
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anonymous

Last Answer : ni bondha
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443 views
2 answers
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Mar 20, 2018
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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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267 views
1 answer

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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273 views
1 answer
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Oct 13, 2019
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anonymous

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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99 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : For a D.C. shunt motor if the excitation is changed torque will change but power will remain constant.
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168 views
1 answer
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Mar 20, 2018
by
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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398 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : At the instant of starting when a D.C. motor is put on supply, it behaves like a low resistance circuit.
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132 views
1 answer
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Mar 20, 2018
by
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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231 views
1 answer
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Mar 20, 2018
by
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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135 views
1 answer
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Mar 20, 2018
by
anonymous

As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit?
Last Answer : As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit a resistance is connected in series with armature.
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189 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The armature torque of the D.C. shunt motor is proportional to armature current.
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215 views
1 answer
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Mar 20, 2018
by
anonymous
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Last Answer : As the load is increased the speed of D.C. shunt motor will reduce slightly.
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144 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Flywheel is used with D.C. compound motor to reduce the peak demand by the motor, compound motor will have to be cumulatively compounded.
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355 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Sparking, is discouraged in a D.C. motor because commutator gets damaged.
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159 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : D.C. Series motor is generally preferred for cranes and hoists.
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1 answer
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Mar 20, 2018
by
anonymous

Last Answer : (b) Clostridium butylicum Lipase Removal of oil stains
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109 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Sparking at the commutator of a D.C. motor may result in damage to commutator segments, damage to commutator insulation, increased power consumption.
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233 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Cumulatively compounded D.C. motor will be suitable along with flywheel for intermittent light and heavy loads.
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181 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Differentially compounded D.C. motor has got maximum self loading property.
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78 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The current drawn by the armature of D.C. motor is directly proportional to the torque required.
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586 views
1 answer
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Mar 20, 2018
by
anonymous
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Last Answer : In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to 25% of the previous value.
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509 views
1 answer
asked
Mar 20, 2018
by
anonymous
