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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100 views
1 answer
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Mar 20, 2018
by
anonymous

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

Last Answer : The speed of a universal motor is generally reduced by using gear trains.
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96 views
1 answer
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Mar 20, 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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234 views
1 answer
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May 1, 2018
by
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
by
anonymous

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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254 views
2 answers
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Dec 16, 2017
by
anonymous

speed control methods of three phase induction motor?
Last Answer : Speed control of three phase induction motor
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363 views
2 answers
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Aug 9, 2017
by
anonymous
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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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270 views
1 answer
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Oct 13, 2019
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anonymous

Last Answer : A universal motor is one which can be operated either on D.C. or A.C. supply at approximately the same speed and output.
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71 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : In a universal motor, the most common cause of brush sparking is open armature winding, shorted armature winding, shorted field winding, high commutator mica.
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147 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The direction of rotation of universal motor can be reversed the by reversing the flow of current through either armature winding or field winding.
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249 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : In D.C. machines fractional pitch winding is used to reduce the sparking.
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355 views
1 answer
asked
Mar 20, 2018
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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146 views
1 answer
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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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137 views
1 answer
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Aug 17, 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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125 views
1 answer
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Jul 26, 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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361 views
4 answers
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Jul 20, 2019
by
anonymous

Last Answer : A universal motor can run on either A.C. or D.C.
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70 views
1 answer
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Mar 20, 2018
by
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
by
anonymous
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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

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

Field control of DC motor
Last Answer : Field control of DC motor
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125 views
2 answers
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Aug 9, 2017
by
anonymous

Last Answer : The wattage of motor for driving domestic sewing machine will be around 100 to 150 W.
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103 views
1 answer
asked
Mar 20, 2018
by
anonymous

Silicon steel is used in electrical machines because it has?
Last Answer : Silicon steel is used in electrical machines because it has low hysteresis loss.
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403 views
1 answer
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Mar 25, 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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481 views
1 answer
asked
May 8, 2018
by
anonymous

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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151 views
1 answer
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Apr 28, 2018
by
anonymous

Last Answer : In variable speed motor a weaker commutating field is needed at low speed than at high speed.
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62 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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389 views
1 answer
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Mar 20, 2018
by
anonymous
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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
by
anonymous

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

Analyze the differences of FOC and DTC. The switching frequency of FOC is 1.3 kHz and the average switching frequency of DTC is the same.
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169 views
0 answers

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 : The motor used for the compressors is capacitor-start capacitor-run motor.
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64 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The shaded pole motor is used for low starting torque.
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63 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The electric motor used in portable drills is universal motor.
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53 views
1 answer
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Mar 20, 2018
by
anonymous

A differentiator is not usually used in control system, because it : - (A) reduces damping (B) increases error (C) reduces gain margin (D) increases input noise
Last Answer : A differentiator is not usually used in control system, because it : - increases input noise
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112 views
1 answer
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Apr 30, 2018
by
anonymous

Regulating-transformers are used in power systems for control of
Last Answer : Regulating-transformers are used in power systems for control of power flow
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149 views
1 answer
asked
Apr 26, 2018
by
anonymous

What are the electromagnetic waves used in remote control?
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64 views
0 answers
asked
Mar 10, 2018
by
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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231 views
1 answer

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
1 answer
asked
Jul 5, 2019
by
anonymous
