Related Questions

In a separately excited generator supplying rated load the armature reaction:
A Is always present
B Is always absent
C May be sometimes present
D None of the above
Armature reaction in a generator results in
A Demagnetization of leading pole tip and magnetization of trailing pole tip
B Demagnetization of trailing pole tip and magnetization of leading pole tip
C Demagnetizing the center of all poles
D Magnetizing the center of all poles
As a result of armature reaction, the reduction in the total mutual air gap flux in a D.C. generator is approximately
A 40 percent
B 25 percent
C 10 percent
D 5 percent
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
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.?
A Lap winding
B Wave winding
C Either of (A) and (B) above
D Depends on other features of design
The armature core of a D.C. generator is usually made of
A Silicon steel
B Copper
C Nonferrous material
D Cast-iron
The number of armature parallel paths in a two-pole D.C. generator having duplex lap winding is
A 2
B 4
C 6
D 8
Fugacity of a component in an ideal gas mixture is euqal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at contant pressure and temperature __________ as its mole fraction increases.
A Decreases
B Decreases exponentially
C Increases
D Remains constant
Relative volatility varies with the concentration of component for an ideal solution. The relative volatity of a binary mixture may be defined as the ratio of vapor pressure of component 'A' to that of component 'B', when
A Only vapor phase follows Raoult's law
B Only liquid phase obeys Dalton's law
C Liquid phase obeys Dalton's law and vapor phase obeys Raoult's law
D Vapor phase obeys Dalton's law and liquid phase obeys Raoult's law
The e.m.f. generated by a shunt wound D.C. generator is E. Now while pole flux remains constant, if the speed of the generator is doubled, the e.m.f. generated will be
A $$\frac{{\text{E}}}{2}$$
B 2E
C Slightly less than E
D E

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