Practice Test: Question Set - 04
1. Which of the following generators will be preferred if they are required to be run in parallel?
- (A) Shunt generators
- (B) Series generators
- (C) Compound generators
- (D) None of the above
2. When two D.C. generators are running in parallel an equalizer bar is used
- (A) To increase the series flux
- (B) To increase the generated e.m.f.
- (C) To reduce the combined effect of armature reaction
of both the machines
- (D) So that the two identical machines will pass
approximately equal currents to the load
3. Laminations of core are generally made of
- (A) Case iron
- (B) Carbon
- (C) Silicon steel
- (D) Stainless steel
4. Fleming's right-hand rule regarding direction of induced e.m.f., correlates
- (A) Magnetic flux, direction of current flow and
resultant force
- (B) Magnetic flux, direction of motion and the
direction of e.m.f. induced
- (C) Magnetic field strength, induced voltage and
current
- (D) Magnetic flux, direction of force and direction of
motion of conductor
5. In a four-pole D.C. machine
- (A) All the four poles are north poles
- (B) Alternate poles are north and south
- (C) All the four poles are south poles
- (D) Two north poles follow two south poles
6. In case of a 4 pole D.C. generator provided with a two layer lap winding with sixteen coils, the pole pitch will be
- (A) 4
- (B) 8
- (C) 16
- (D) 32
7. The demagnetizing component of armature reaction in a D.C. generator
- (A) Reduces generator e.m.f.
- (B) Increases armature speed
- (C) Reduces interpoles flux density
- (D) Results in sparking trouble
8. For the parallel operation of two or more D.C. compound generators, we should ensure that
- (A) Voltage of the incoming generator should be same as
that of bus bar
- (B) Polarity of incoming generator should be same as
that of bus bar
- (C) All the series fields should be run in parallel by
means of equalizer connection
- (D) Series fields of all generators should be either on
positive side or negative side of the armature
9. The e.m.f. generated in a D.C. generator is directly proportional to
- (A) Flux/pole
- (B) Speed of armature
- (C) Number of poles
- (D) All of the above
10. A cumulatively compounded long shunt generator when operating as a motor would be
- (A) Cumulatively compounded long shunt
- (B) Differentially compounded long shunt
- (C) Cumulatively compounded short shunt
- (D) Differentially compounded short shunt
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