MCQOPTIONS
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MCQOPTIONS
This section includes 18 Mcqs, each offering curated multiple-choice questions to sharpen your Dc Machines knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
To get the speed of DC motor below the normal speed without wastage of electrical energy we use __________________ |
| A. | Ward Leonard control |
| B. | Rheostatic control |
| C. | Any of the Ward Leonard or rheostatic method can be used |
| D. | Not possible |
| Answer» B. Rheostatic control | |
| 2. |
Starting gear used in Ward Leonard method___________ |
| A. | Is of small size |
| B. | Is of large size |
| C. | Size depends on application |
| D. | Is absent |
| Answer» E. | |
| 3. |
Efficiency of Ward Leonard method is ____________ |
| A. | Higher than rheostatic control method but lower than shunted field control method |
| B. | Lower than rheostatic control method |
| C. | Higher than rheostatic control method and shunted field control method |
| D. | Depends on load |
| Answer» D. Depends on load | |
| 4. |
In Ward Leonard speed control method for increasing the speed of the motor ______________ |
| A. | Reduce armature voltage |
| B. | Increase armature voltage |
| C. | Increase field current |
| D. | Decrease field current |
| Answer» E. | |
| 5. |
WARD_LEONARD_METHOD_IS_AN_IDEAL_CHOICE_FOR_MOTOR_WHICH_UNDERGOES_FREQUENT_STARTING,_STOPPING,_SPEED_REVERSAL.?$ |
| A. | True |
| B. | False |
| Answer» B. False | |
| 6. |
To get the speed of DC motor below the normal speed without wastage of electrical energy we use __________________$ |
| A. | Ward Leonard control |
| B. | Rheostatic control |
| C. | Any of the Ward Leonard or rheostatic method can be used |
| D. | Not possible |
| Answer» B. Rheostatic control | |
| 7. |
Starting_gear_used_in_Ward_Leonard_method___________$ |
| A. | Is of small size |
| B. | Is of large size |
| C. | Size depends on application |
| D. | Is absent |
| Answer» E. | |
| 8. |
The disadvantage of the Ward Leonard control method is ___________ |
| A. | High initial cost |
| B. | High maintenance cost |
| C. | Low efficiency at high loads |
| D. | High cost, high maintenance and low efficiency |
| Answer» E. | |
| 9. |
In Ward Leonard control of DC motor, 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. | Cannot be determined |
| Answer» B. Core losses of motor | |
| 10. |
Ward Leonard control is basically a _____________ |
| A. | Voltage control method |
| B. | Field diverter method |
| C. | Field control method |
| D. | Armature resistance control method |
| Answer» B. Field diverter method | |
| 11. |
Speed control by Ward Leonard method, can give uniform speed variation _______________ |
| A. | In both directions |
| B. | In one direction |
| C. | Below normal speed only |
| D. | Above normal speed only. |
| Answer» B. In one direction | |
| 12. |
Efficiency of Ward Leonard method is ___________? |
| A. | Higher than rheostatic control method but lower than shunted field control method |
| B. | Lower than rheostatic control method |
| C. | Higher than rheostatic control method and shunted field control method |
| D. | Depends on load |
| Answer» D. Depends on load | |
| 13. |
Speed-power characteristic for Ward Leonard speed control method _________________ |
| A. | Will start from origin |
| B. | Will start from some positive value on power axis |
| C. | Will start from some positive value on speed axis |
| D. | Depends on other parameters |
| Answer» B. Will start from some positive value on power axis | |
| 14. |
Reducing the field current will give us _______________ |
| A. | Constant torque and variable power speed control |
| B. | Constant torque speed control |
| C. | Variable power speed control |
| D. | Constant power speed control |
| Answer» C. Variable power speed control | |
| 15. |
Reducing the armature voltage will give us _______________ |
| A. | Variable torque speed control |
| B. | Constant torque speed control |
| C. | Variable and constant both can be achieved |
| D. | Cannot comment on torque |
| Answer» C. Variable and constant both can be achieved | |
| 16. |
In Ward Leonard speed control method for lowering the speed of the motor ______________ |
| A. | Reduce armature voltage |
| B. | Increase armature voltage |
| C. | Increase field current |
| D. | Decrease field current |
| Answer» B. Increase armature voltage | |
| 17. |
Which of the following component is not used in Ward Leonard method? |
| A. | AC motor |
| B. | DC generator |
| C. | DC motor |
| D. | AC generator |
| Answer» E. | |
| 18. |
Ward Leonard method is ___________ |
| A. | Armature control method |
| B. | Field control method |
| C. | Combination of armature control method and field control method |
| D. | Totally different from armature and field control method |
| Answer» D. Totally different from armature and field control method | |