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

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1 Answer

Answer :

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

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Related questions

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.

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 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.

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.

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.

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.

In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis, when?

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.

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.

If brushes of a D.C. generator are moved in order to bring these brushes in magnetic neutral axis, there will be?

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 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...

Description : For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f. ?

Last Answer : Wave winding

In a D.C. generator, the iron losses mainly take place in?

Last Answer : In a D.C. generator, the iron losses mainly take place in armature rotor.

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.

The eddy current loss in a dc generator is 400 W at 40 Hz frequency of reversal and constant flux density.

Description : The eddy current loss in a dc generator is 400 W at 40 Hz frequency of reversal and constant flux density. When frequency is increased to 50 Hz., eddy current loss is :  (A) 256 W (B) 320 W (C) 500 W (D) 625 W

Last Answer : The eddy current loss in a dc generator is 400 W at 40 Hz frequency of reversal and constant flux density. When frequency is increased to 50 Hz., eddy current loss is : 625 W

The fall in speed of a dc generator due to increase in load can be corrected by

Description : The fall in speed of a dc generator due to increase in load can be corrected by  (1) cooling the armature.. (2) increasing the excitation. (3) reducing the load voltage. (4) increasing the input to the prime mover

Last Answer : It   can  be  corrected  by  increasing  the  input  to  the  prime  mover.

D.C. generators are installed near the load centres to reduce?

Last Answer : D.C. generators are installed near the load centres to reduce line losses.

State the function of commutator in DC generator and name the material used for commutator.

Description : State the function of commutator in DC generator and name the material used for commutator.

Last Answer : Function of Commutator: Commutator converts AC induced in armature winding into DC for external load. Material: i) Commutator segments are made up of Copper. ii) Commutator segments are insulated from each other by Mica.

A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2

Description : 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

In a DC generator the windings of interpoles are connected :

Description : In a DC generator the windings of interpoles are connected :  (A) in series with main field winding, to create a pole,of same polarity as the main pole ahead in the direction of rotation.  ... winding, to create a pole of opposite polarity as the main pole ahead in the direction of rotation.

Last Answer : In a DC generator the windings of interpoles are connected :  in series with the armature winding, to create a pole of same polarity as the main pole ahead in the direction of rotation. 

The terminal characteristics of a dc generator suitable for electric welders is

Description : The terminal characteristics of a dc generator suitable for electric welders is (A) separately excited generator (B) shunt generator (C) series generator (D) differentially compounded generator

Last Answer : The terminal characteristics of a dc generator suitable for electric welders is differentially compounded generator

What is the difference between an AC and DC generator?

Description : What is the difference between an AC and DC generator?

Last Answer : The generator which generates DC voltage is called DC generator and generator which generates AC voltage is called AC generator (or) Alternator. In DC generator armature is rotated and field winding ... generator. A DC generator can generate low voltages but an AC generator can generate upto 11kv.

What is the principle of DC generator?

Description : What is the principle of DC generator?

Last Answer : principle

From which material field coils of DC generator are made of?

Description : From which material field coils of DC generator are made of?

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

Why is the armature of DC generator laminated?

Description : Why is the armature of DC generator laminated?

Last Answer : The armature of DC generator is laminated to reduce eddy current losses.

In a separately excited generator supplying rated load the armature reaction?

Last Answer : In a separately excited generator supplying rated load the armature reaction is always present.

In over compounded generator, full load terminal voltage is?

Last Answer : In over compounded generator, full load terminal voltage is more than no load terminal voltage.

When two D.C. series generators are running in parallel, an equilizer bar is used?

Last Answer : If  equalising bar is connected to the 2 DC generators  the current will be equal in 2 generators irrespective of parallel connection so that we connect equaliser bar

In D.C. generators the polarity of the interpoles?

Last Answer : In D.C. generators the polarity of the interpoles is the same as that of the main pole ahead.

For the parallel operation of two or more D.C. compound generators, we should ensure that?

Last Answer : For the parallel operation of two or more D.C. compound generators, we should ensure that series fields of all generators should be either on positive side or negative side of the armature.

Compensating windings are used in D.C. generators?

Last Answer : Compensating windings are used in D.C. generators to neutralise the cross-magnetising effect of the armature reaction.

D.C. generators are connected to the busbars or disconnected from them only under the floating condition?

Last Answer : D.C. generators are connected to the busbars or disconnected from them only under the floating condition to avoid sudden loading of the primemover, to avoid mechanicaljerk to the shaft, to avoid burning of switch contacts.

In D.C. generators, the brushes on commutator remain in contact with conductors which?

Last Answer : In D.C. generators, the brushes on commutator remain in contact with conductors which lie under interpolar region.

In D.C. generators, current to the external circuit from armature is given through?

Last Answer : In D.C. generators, current to the external circuit from armature is given through commutator commutator.

In D.C. generators the pole shoes are fastened to the pole core by?

Last Answer : In D.C. generators the pole shoes are fastened to the pole core by counter sunk screws.

D.C. generators are normally designed for maximum efficiency around?

Last Answer : D.C. generators are normally designed for maximum efficiency around full-load.

Armature reaction in a generator results in?

Last Answer : Armature reaction in a generator results in demagnetisation of leading pole tip and magnetisation of trailing pole tip.

A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave?

Description : A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave?

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.

In case of a flat compounded generator?

Last Answer : In case of a flat compounded generator voltage remains constant irrespective of the load.

An exciter for a turbo generator is a?

Last Answer : An exciter for a turbo generator is a shunt generator.

A cumulatively compounded long shunt generator when operating as a motor would be?

Last Answer : A cumulatively compounded long shunt generator when operating as a motor would be differentially compounded long shunt.