A. Voltage control method
B. Field control method
C. Armature control method
D. All above methods
Related Mcqs:
- Speed control by Ward Leonard method gives uniform speed variation_____________?
A. in one direction
B. in both directions
C. below normal speed only
D. above normal speed only - The speed of a D.C. shunt motor more than its full-load speed can be obtained by_____________?
A. decreasing the field current
B. increasing the field current
C. decreasing the armature current
D. increasing the armature current - The speed of a motor falls from 1100 r.p.m. at no-load to 1050 r.p.m. at rated load. The speed regulation of the motor is______________?
A. 2.36%
B. 4.76%
C. 6.77%
D. 8.84% - The speed of a D.C. shunt motor is required to be more than full load speed. This is possible by______________?
A. reducing the field current
B. decreasing the armature current
C. increasing the armature current
D. increasing the excitation current
E. none of the above methods - Which of the following method is used for the speed control of DC shunt motor?
A. voltage control method
B. flux control method
C. rheostat control method
D. all of the above - If the terminals of armature of D.C. motor are interchanged, this action will offer following kind of braking?
A. regenerative
B. plugging
C. dynamic braking
D. none of the above
E. any of the above - For constant torque drive which speed control method is preferred ?
A. Field control
B. Armature voltage control
C. Shunt armature control
D. Mechanical loading system - Ward Leonard method of speed control is basically a______________?
A. field control method
B. armature controlled method
C. field diverter
D. frequency control method - Which one of the following is not the function of pole shoes in a D.C. machine ?
A. To reduce eddy current loss
B. To support the field coils
C. To spread out flux for better uniformity
D. To reduce the reluctance of the magnetic path - The hysteresis loss in a D.C. machine least depends on____________?
A. Frequency of magnetic reversals
B. Maximum value of flux density
C. Volume and grade of iron
D. Rate of flow of ventilating air
