For starting a D.C. motor a starter is required because?

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asked Mar 20, 2018 by anonymous

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asked Mar 20, 2018 by anonymous

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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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asked Mar 15, 2018 by anonymous

Why does induction motor have high starting current?

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asked Mar 20, 2018 by anonymous

When a D.C. series motor is connected to A.C. supply, the power factor will be low because of?

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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asked Mar 20, 2018 by anonymous

If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens?

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asked Mar 20, 2018 by anonymous

In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to?

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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asked Mar 20, 2018 by anonymous

The speed of a D.C. series motor is?

Last answer: The speed of a D.C. series motor is inversely proportional to the armature current.

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asked Mar 20, 2018 by anonymous

By looking at which part of the motor, it can be easily confirmed that a particular motor is D.C. motor?

Last answer: By looking at Commutator part of the motor, it can be easily confirmed that a particular motor is D.C. motor.

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asked Mar 20, 2018 by anonymous

In a D.C. shunt motor, speed is?

Last answer: In a D.C. shunt motor, speed is independent of armature current.

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asked Mar 20, 2018 by anonymous

If a D.C. motor is connected across the A.C. supply it will?

Last answer: If a D.C. motor is connected across the A.C. supply it will burn due to heat produced in the field winding by eddy currents.

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asked Mar 20, 2018 by anonymous

A D.C. series motor is that which?

Last answer: A D.C. series motor is that which has its field winding consisting of thick wire and less turns.

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asked Mar 20, 2018 by anonymous

If the field of a D.C. shunt motor gets opened while motor is running?

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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asked Mar 20, 2018 by anonymous

If a D.C. series motor is operated on A.C. supply, it will?

Last answer: If a D.C. series motor is operated on A.C. supply, it will spark excessively, have poor efficiency, have poor power factor.

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asked Mar 20, 2018 by anonymous

The speed of a D.C. motor can be controlled by varying

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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115 views 1 answer

asked Mar 20, 2018 by anonymous

In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will?

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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148 views 1 answer

asked Mar 20, 2018 by anonymous

The speed of a D.C. shunt motor can be increased by?

Last answer: The speed of a D.C. shunt motor can be increased by increasing the resistance in field circuit.

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88 views 1 answer

asked Mar 20, 2018 by anonymous

In a differentially compounded D.C. motor, if shunt field suddenly opens?

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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asked Mar 20, 2018 by anonymous

Sparking at the commutator of a D.C. motor may result in?

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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asked Mar 20, 2018 by anonymous

In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be?

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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asked Mar 20, 2018 by anonymous

What will happen if the back e.m.f. of a D.C. motor vanishes suddenly?

Last answer: The armature may burn if the back e.m.f. of a D.C. motor vanishes suddenly.

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378 views 1 answer

anonymous · Answer 1 · 2018-03-20T20:06:08+0000

For starting a D.C. motor a starter is required because it limits the starting current to a safe value.

For starting a D.C. motor a starter is required because?

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