A. Increase in length of air gap at pole tips
B. Increasing reluctance of pole tips
C. Compensating windings
D. Interpoles
E. All of the above
Related Mcqs:
- In D.C. machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made____________?
A. equal to that of armature mmf
B. less in comparison with the armature mmf
C. large in comparison with the armature mmf
D. none of the above - By which of the following methods the temperature rise of windings and other parts may be determined ?
A. Thermometer method
B. Resistance method
C. Embedded temperature detector method
D. Any of the above - cooling is the process of dissipating the armature and field winding losses to a cooling medium circulating within the winding insulation wall______________?
A. Direct
B. Indirect
C. Conventional
D. Any of the above - The weight of copper of both armature and field windings decreases with __________ in number of poles?
A. increase
B. decrease
C. either of the above
D. none of the above - The laminations of the armature of a D.C. machine are usually ___________ thick?
A. 0.1 to 0.2 mm
B. 0.2 to 0.3 mm
C. 0.3 to 0.4 mm
D. 0.4 to 0.5 mm - The efficiency of a machine should be as ____________ as possible to reduce the operating cost?
A. high
B. low
C. either of the above
D. none of the above - Which of the following methods is used for air cooling of turbo-alternators ?
A. One sided axial ventilation
B. Two sided axial ventilation
C. Multiple inlet system
D. All of the above - Which of the following methods does not take into account the maximum temperature rise under variable load conditions ?
A. Equivalent power method
B. Equivalent current method
C. Method of average losses
D. Equivalent torque method - By which of the following methods motor rating for variable load drives can be determined ?
A. Method of average losses
B. Equivalent current method
C. Equivalent torque method
D. Equivalent power method
E. All of the above - Which of the following methods is most accurate ?
A. Equivalent current method
B. Equivalent power method
C. Equivalent torque method
D. Method of average losses
