Magnetic field in a D.C. generator is produced by?

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2 Answers

Answer :

Magnetic field in a D.C. generator is produced by electromagnets.

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Answer :

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Flashing the field of D.C. generator means?

Last Answer : Flashing the field of D.C. generator means creating residual magnetism by a D.C. source.

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Last Answer : In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis, when there is no load on|he generator.

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Last Answer : Field coils of DC generator are usually made of copper.

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Last Answer : A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave will be of 5 Hz.

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Last Answer : If brushes of a D.C. generator are moved in order to bring these brushes in magnetic neutral axis, there will be crossmagnetisation as well as demagnetising.

In a D.C. generator in case the resistance of the field winding is increased, then output voltage will?

Last Answer : In a D.C. generator in case the resistance of the field winding is increased, then output voltage will decrease.

Why does the magnetic field flow from north to south?

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Last Answer : Magnetic field strength is the force experienced by a unit N-pole when placed at any point in a magnetic field is known as magnetic field strength or magnetizing force. Magnetising force or magnetic field ... unit of length is metre. So the unit of magnetic field strength is ampere turns per metre.

Which of the following laws relates the magnetic field to the magnitude, direction, length, and proximity

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Which of the following statements is not characteristic of a static magnetic field?

Description : Which of the following statements is not characteristic of a static magnetic field? (A) It is solenoidal. (B) It is conservative. (C) It has no sinks or sources. (D) Flux lines are always closed.

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To avoid the effect of stray magnetic field in A.C. bridges we can use?

Last Answer : To avoid the effect of stray magnetic field in A.C. bridges we can use magnetic screening.

How can a magnetic field be used to generate an electric current?

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Last Answer : Magnetic  field  can  be  used  to  generate  electric  current  on  a  condition  that  it  is  on  a  rate  of  changing  magnetic  flux.  (Faraday's  law)

The critical resistance of the D.C. generator is the resistance of?

Last Answer : The critical resistance of the D.C. generator is the resistance of field.

If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed will be?

Description : If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed will be?

Last Answer : If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed will be zero.

A 220 V D.C. generator is run at full speed without any excitation. The open circuit voltage will be?

Last Answer : A 220 V D.C. generator is run at full speed without any excitation. The open circuit voltage will be about 2 V.

In a level compounded D.C. generator, full load terminal voltage is?

Last Answer : In a level compounded D.C. generator, full load terminal voltage is equal to no-load terminal voltage.

A D.C. generator can be considered as?

Last Answer : A D.C. generator can be considered as rotating amplifier.

In a D.C. generator the critical resistance refers to the resistance of?

Last Answer : In a D.C. generator, the critical resistance refers to the resistance of field.

If a D.C. generator fails to build up the probable cause could not be?

Last Answer : If a D.C. generator fails to build up the probable cause could not be field resistance less than the critical resistance.

The e.m.f. generated in a D.C. generator is directly proportional to?

Last Answer : The e.m.f. generated in a D.C. generator is directly proportional to speed of armature.

In a D.C. generator the number of mechanical degrees and electrical degrees will be the same when?

Last Answer : In a D.C. generator the number of mechanical degrees and electrical degrees will be the same when number of poles is 2.

D.C. generator generally preferred for charging automobile batteries is?

Last Answer : D.C. generator generally preferred for charging automobile batteries is long shunt compound generator.

The armature core of a D.C. generator is usually made of?

Last Answer : The armature core of a D.C. generator is usually made of silicon steel.

In a D.C. generator the ripples in the direct e.m.f. generated are reduced by?

Last Answer : In a D.C. generator the ripples in the direct e.m.f. generated are reduced by using carbon brushes of superior quality.

The demagnetising component of armature reaction in a D.C. generator?

Last Answer : The demagnetising component of armature reaction in a D.C. generator reduces generator e.m.f.

In case of a 4-pole D.C. generator provided with a two layer lap winding with sixteen coils, the pole pitch will be?

Last Answer : In case of a 4-pole D.C. generator provided with a two layer lap winding with sixteen coils, the pole pitch will be 8.

For a D.C. generator when the number of poles and the number of armature conductors is fixed...

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The condition for maximum efficiency for a D.C. generator is?

Last Answer : The condition for maximum efficiency for a D.C. generator is variable losses equal to constant losses.

The total losses in a well designed D.C. generator of 10 kW will be nearly?

Last Answer : The total losses in a well designed D.C. generator of 10 kW will be nearly 500 W.

In D.C. generators on no-load, the air gap flux distribution in space is?

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If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens?

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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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