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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1 answer
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May 3, 2018
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anonymous

Last Answer : The armature torque of the D.C. shunt motor is proportional to armature current.
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210 views
1 answer
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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
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Mar 20, 2018
by
anonymous

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

Last Answer : The armature voltage control of D.C. motor provides constant torque drive.
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91 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
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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
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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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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
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
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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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146 views
1 answer
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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
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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
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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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106 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

The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is (A) 0.25 pu (B) 0.5 pu (C) 1.0 pu (D) 1.5 pu
Last Answer : The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is 0.5 pu
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98 views
1 answer
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Apr 28, 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
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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
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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
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Apr 23, 2020
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
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Jul 27, 2019
by
anonymous
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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
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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
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Mar 20, 2018
by
anonymous

Last Answer : Series motor has got maximum self relieving property.
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193 views
1 answer
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Mar 20, 2018
by
anonymous

The synchronous motor will develop maximum power when the load angle is?
Last Answer : The synchronous motor will develop maximum power when the load angle is 900.
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223 views
1 answer
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Mar 18, 2018
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anonymous

The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole) (A) has q -axis current only (B) has d -axis current only (C) has both d and q axis currents (D) cannot be divided between q and d axis currents
Last Answer : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole) has d -axis current only
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193 views
1 answer
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Apr 29, 2018
by
anonymous

The secondary of a current transformer is always short-circuited under operating conditions because it?
Last Answer : The secondary of a current transformer is always short-circuited under operating conditions because it avoids core saturation and high voltage induction.
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107 views
1 answer
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Mar 19, 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
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Mar 20, 2018
by
anonymous

State maximum power transfer theorem for DC circuit.
Last Answer : Maximum power transfer theorem for DC circuit: The maximum power transfer theorem states that the source or a network transfers maximum power to load only when the load resistance is equal ... removed (disconnected) ii) All internal independent sources are replaced by their internal resistances.
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110 views
1 answer
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Sep 6, 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
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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
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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
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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
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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
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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
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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
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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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115 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
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Mar 20, 2018
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 : In case the conditions for maximum power for a D.C. motor are established, the efficiency of the motor will be less than 50%.
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177 views
1 answer
asked
Mar 20, 2018
by
anonymous

A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is
Last Answer : Please show the solution for this question
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515 views
2 answers
asked
Apr 29, 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 : When a D.C. series motor is connected to A.C. supply, the power factor will be low because of high inductance of field and armature circuits.
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119 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Open circuited armature coil of a D.C. machine is identified by the scarring of the commutator segment to which open circuited coil is connected and indicated by a spark completely around the commutator.
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158 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The armature core of a D.C. generator is usually made of silicon steel.
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151 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The demagnetising component of armature reaction in a D.C. generator reduces generator e.m.f.
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121 views
1 answer
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Mar 20, 2018
by
anonymous

205 views
0 answers
asked
Mar 20, 2018
by
anonymous
