### Dc Genertors Objectives Part 04

**61 . ** The condition for maximum efficiency in case of dc generator is **Variable loss= Constant loss.**

**62 .** A dc generator running at fixed speed and with fixed shunt field resistance has** short circuit current is less than the maximum load current **that it can feed.

**63 . ** In a dc machine, the angle between the stator and rotor field is **90º.**

**64 .** A dc shunt generator delivers 395 A at 250 V and the resistance of the shunt field and armature 50Ω and 0.05Ω respectively. The generated emf will be **270V.**

**65 .** In a level compound generator, the terminal voltage at half full load is **more than no load voltage.**

**66 .** In a generator, the** windage loss is proportional to square of armature speed.**

**67 .** When field resistance of a dc shunt generator is increased beyond its critical value the generator** will not build up.**

**68 . ** The number of armature parallel paths in a two-pole dc generator provided with duplex lap winding will be** 4.**

**69 .** When two shunt generators are operating in parallel, the easiest way to shift load from one generator to the other is to adjust their **field rheostats.**

**70 . ** The number of armature parallel paths is 12 pole dc generator provided with triplex lap winding will be** 36.**

**71 . ** In a dc generator the brushes are always placed along** Magnetic neutral axis (MNA).**

**72 .** If two generators are running in parallel and field of one of the generators is weakened too much, then it will run **as a motor in same direction.**

**73 . ** In dc generators, the** brushes remain in contact with conductors **which lie in the interpolar gaps.

**74 .** Among the series and shunt generators, **shunt generator has the better regulation.**

**75 .** The armature reaction of an unsaturated dc machine is **cross-magnetizing.**

**76 .** A generator is said to be flat compounded when the **voltage remains constant irrespective of the load on the generator.**

**77 . ** Iron losses in dc machine take place in** armature rotor.**

**78 . ** Eddy current loss in a dc shunt generator occurs in magnetic as well as non**-magnetic conductor material.**

**79 . ** A dc shunt generator remained inoperative for long time as a result of which residual magnetism was lost. The residual magnetism can be restored by** connecting the shunt field to the battery.**

**80 . ** The change in speed of a dc generator due to increased loads is corrected by** increasing input power of the prime mover.**