Ward Leonard method of speed control is basically a______________?

Related Mcqs:

1. 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

2. Ward-Leonard control is basically a____________?

   A. voltage control method
   B. field divertor method
   C. field control method
   D. armature resistance control method

3. In Ward-Leonard control the lower limit of speed is imposed by________?

   A. residual magnetism of the generator
   B. core losses of motor
   C. mechanical losses of motor and generator together
   D. all of the above

4. The main disadvantage of the Ward-Leonard control method is______________?

   A. high initial cost
   B. high maintenance cost
   C. low efficiency at Hght loads
   D. all of the above

5. 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

6. 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%

7. 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

8. Which of the following method of speed control of D.C. machine will offer minimum efficiency ?

   A. Voltage control method
   B. Field control method
   C. Armature control method
   D. All above methods

9. 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

10. 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