1 Answer

Answer :

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

Like 0 like

Related Questions

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

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

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.

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

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

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

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.

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

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

Description : In DC generators lamination core are generally made of?

Last Answer : In DC generators lamination core are generally made of silicon steel.

Description : DC GENERATORS MCQ

Last Answer : 101. Wave winding is composed of (a) any even number of conductors (b) any odd number of conductors (c) that even number which is exact multiple of poles + 2 (d) that even number ... increase the field resistance (c) increase the speed of primemover (d) check armature insulation resis¬tance Ans: a

Description : Identify the increasing order of voltage regulation of the following dc generators a same load :  (A) differential compound, shunt and under compound  (B) shunt, differential compound and ... C) under compound, shunt and differential compound  (D) shunt, under compound and differential compound

Last Answer : Identify the increasing order of voltage regulation of the following dc generators a same load : under compound, shunt and differential compound 

Description : Laminations of core are generally made of (a) case iron (b) carbon (c) silicon steel (d) stainless steel

Description : The armature of D.C. generator is laminated to (a) reduce the bulk (b) provide the bulk (c) insulate the core (d) reduce eddy current loss

Description : Eddy currents are induced in the pole shoes of a D.C. machine due to?

Last Answer : Eddy currents are induced in the pole shoes of a D.C. machine due to relative rotation between field and armature.

Description : The field coils of D.C. generator are usually made of (a) mica (b) copper (c) cast iron (d) carbon

Last Answer : Ans: b (b) copper

Description : The resistance of armature winding depends on (a) length of conductor (b) cross-sectional area of the conductor (c) number of conductors (d) all of the above

Description : Which of the following could be lamina-proximately the thickness of laminations of a D.C. machine ? (a) 0.005 mm (b) 0.05 mm (c) 0.5 m (d) 5 m

Description : Why are generators rated in kVA not in kW ?

Last Answer : Because It's rating of generator kva is apparent power. Kw is active power which we use. And one is kvar reactive power.

Description : Two synchronous generators G1, G2 are operating in parallel and are equally sharing KVAR (Lag) component of load. To shift part of KVAR from G2 to G1, while keeping terminal voltage fixed, the following action must be done

Last Answer : Two synchronous generators G1, G2 are operating in parallel and are equally sharing KVAR (Lag) component of load. To shift part of KVAR from G2 to G1, while keeping terminal voltage fixed, the following action must be done Raise If1 and lower If2

Last Answer : Large capacity generators are invariably hydrogen cooled.

Last Answer : Generators for peak load plants are usually designed for maximum efficiency at 50 to 75 percent full load.

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

Description : How Generators Work

Last Answer : How Generators Work Generators are devices which produce electricity. They produce electricity by converting mechanical energy from power sources. Examples would be steam, water, wind and gasoline. These ... can also be used for recreational purposes. Examples would be camping, boating or fishing.

Description : Two synchronous generators operating in parallel supply a common load of 2.5 MW. The frequency-power characteristics have a common slope of 1 MW/Hz and the no-load frequencies of the generators are 51.5 Hz and 51.0 Hz, ... system frequency is (A) 50 Hz (B) 51 Hz (C) 51.25 Hz (D) 51.5 Hz

Last Answer : Two synchronous generators operating in parallel supply a common load of 2.5 MW. The frequency-power characteristics have a common slope of 1 MW/Hz and the no-load frequencies of the generators are 51.5 Hz and 51.0 Hz, respectively. Then the system frequency is 50 Hz

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.

Last Answer : In a four-pole D.C. machine alternate poles are north and south.

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

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.

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

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.

Last Answer : Brushes of D.C. machines are made of carbon.

Last Answer : Iron losses in a D.C. machine are independent of variations in load.

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

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.

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.

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

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

Last Answer : In a D.C. machine stray loss is the sum of iron loss and mechanical loss.

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

Last Answer : To avoid formation of grooves in the commutator of a D.C. machine the brushes of opposite polarity should track each other.

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

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

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

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.

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

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.

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

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.

Last Answer : Satisfactory commutation of D.C. machines requires brushes should be of proper grade and size, brushes should smoothly run in the holders, smooth, concentric commutator properly undercut.

Show MoreNext Page → ← Prev Page