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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331 views
1 answer
asked
May 3, 2018
by
anonymous

Last Answer : In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be more than full-load current.
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367 views
1 answer
asked
Mar 20, 2018
by
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

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

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
asked
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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134 views
1 answer
asked
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
asked
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
asked
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
asked
Mar 20, 2018
by
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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135 views
1 answer
asked
Mar 20, 2018
by
anonymous

The normal value of the armature resistance of a d.c. motor is?
Last Answer : The normal value of the armature resistance of a d.c. motor is 0.5.
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2.9k views
1 answer
asked
Mar 26, 2018
by
anonymous

Last Answer : When the armature of a D.C. motor rotates, e.m.f. induced is back e.m.f.
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203 views
1 answer
asked
Mar 20, 2018
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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140 views
2 answers
asked
Apr 23, 2020
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
asked
Aug 25, 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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115 views
2 answers
asked
Jul 27, 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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2.7k views
1 answer
asked
Jul 5, 2019
by
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
asked
Mar 20, 2018
by
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
asked
Mar 20, 2018
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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145 views
2 answers
asked
Apr 24, 2020
by
anonymous
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Last Answer : Torque developed by a D.C. motor depends upon magnetic field, active length of the conductor, current flow through the conductors, number of conductors, radius of armature.
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638 views
1 answer
asked
Mar 20, 2018
by
anonymous

Why a dc series motor has a high starting torque?
Last Answer : motor
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86 views
1 answer
asked
Mar 15, 2018
by
anonymous

Last Answer : In a A.C. series motor armature coils are usually connected to commutator through resistance.
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161 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The mechanical power developed by a shunt motor will be maximum when the ratio of back e.m.f. to applied voltage is 0.5.
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324 views
1 answer
asked
Mar 20, 2018
by
anonymous

In a double squirrel cage induction motor, good starting torque is produced as (A) Large current flows through the outer high resistance winding. (B) Large current flows through the inner high ... the outer high resistance winding. (D) Large current flows through the inner low resistance winding.
Last Answer : In a double squirrel cage induction motor, good starting torque is produced as Large current flows through the outer high resistance winding.
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136 views
1 answer
asked
May 8, 2018
by
anonymous
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Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be
Last Answer : Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be 25 N -m
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422 views
1 answer
asked
Apr 29, 2018
by
anonymous
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The torque developed by any 3-phase induction motor at 0.8 p.u. slip is (A) Full-load torque (B) unstable torque (C) starting torque (D) break down
Last Answer : The torque developed by any 3-phase induction motor at 0.8 p.u. slip is unstable torque
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3.1k views
1 answer
asked
Apr 28, 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

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
asked
Mar 20, 2018
by
anonymous

Last Answer : In repulsion motor, maximum torque is developed when brush axis is at 45° electrical to the field axis.
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116 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : Capacitor start motor has high torque in starting
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133 views
1 answer
asked
Sep 13, 2017
by
anonymous

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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503 views
1 answer
asked
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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582 views
1 answer
asked
Mar 20, 2018
by
anonymous

A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ohm. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is
Last Answer : A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ohm. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.87
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127 views
1 answer
asked
May 8, 2018
by
anonymous

In dc machines, the armature windings are placed on the rotor because of the necessity for (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque
Last Answer : 3 Commutation
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291 views
2 answers
asked
May 1, 2018
by
anonymous

The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors rotating at 600 rpm and with 1 Wb flux per pole is (1) 1000V (2) 100V (3) 600V (4) 10,000V
Last Answer : The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors rotating at 600 rpm and with 1 Wb flux per pole is 1000V
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370 views
1 answer
asked
Apr 29, 2018
by
anonymous

Aluminium is not used as winding wire for the armature of a dc machine because (1) aluminium has low resistivity (2) a large winding space is taken by aluminium conductors and creates ... ) the thermal conductivity of aluminium is low (4) aluminium has low conductivity as compared to copper
Last Answer : Aluminium is not used as winding wire for the armature of a dc machine because (2) a large winding space is taken by aluminium conductors and creates jointing problems (3) the thermal conductivity of aluminium is low (4) aluminium has low conductivity as compared to copper
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621 views
1 answer
asked
Apr 29, 2018
by
anonymous

Why is the armature of DC generator laminated?
Last Answer : The armature of DC generator is laminated to reduce eddy current losses.
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176 views
1 answer
asked
Mar 3, 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
asked
Mar 20, 2018
by
anonymous

Last Answer : In D.C. shunt motors as load is reduced the speed will remain almost constant.
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145 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a synchronous motor, the armature current has large values for high and low excitation.
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138 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The armature current of the synchronous motor has large values for low and high excitation.
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107 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a manual shunt motor starter over load relay is connected in series and no volt relay in parallel with the load.
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76 views
1 answer
asked
Mar 20, 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
asked
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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122 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : A synchronous motor can develop synchronous torque at synchronous speed.
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114 views
1 answer
asked
Mar 20, 2018
by
anonymous

The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?
Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.
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302 views
1 answer
asked
Mar 20, 2018
by
anonymous

The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as?
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106 views
0 answers
asked
Mar 20, 2018
by
anonymous

What is the maximum value of torque angle in synchronous motor?
Last Answer : The maximum value of torque angle in synchronous motor is 90 degrees electrical.
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1.5k views
1 answer
asked
Mar 18, 2018
by
anonymous
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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
1 answer
asked
Apr 29, 2018
by
anonymous
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