Computer Programming MCQs

5739 MCQs  (Page 261 of 574)

Which of the following methods may be adopted to reduce the effects of armature reaction ?
A. increase in length of air gap at pole tips
B. increasing reluctance of pole tips
C. compensating windings
D. interpoles
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
In D.C. machines the usual limit of slot pitch is________________?
A. Between 5 to 10 mm
B. Between 10 to 15 mm
C. Between 15 to 20 mm
D. Between 25 to 35 mm
D.C. machines designed with a large value of air gap length have_____________?
A. Worst, ventilation
B. Poor ventilation
C. Better ventilation
D. None of the above