MCQOPTIONS
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MCQOPTIONS
This section includes 5 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Machines knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
If the DC excitation is suddenly dropped to 0, the three phase alternator _________ |
| A. | runs as motor |
| B. | stops to zero speed in few seconds |
| C. | continues to run as motor but at lower speed |
| D. | no change in the operating conditions |
| Answer» B. stops to zero speed in few seconds | |
| 2. |
The main exciter used in DC excitation is ________ |
| A. | field on stator |
| B. | armature on stator |
| C. | field on rotor |
| D. | field on poles |
| Answer» B. armature on stator | |
| 3. |
The brushless excitation and conventional DC excitation systems are comparable but one significant change is _______ |
| A. | pilot exciter is brushless permanent magnet motor |
| B. | three phase rectifier feeds directly to main exciter |
| C. | a three phase rectifier is fed by main exciter |
| D. | no direct rectification is provided to the pilot exciter |
| Answer» B. three phase rectifier feeds directly to main exciter | |
| 4. |
What are the main problems faced by conventional DC exciters? |
| A. | cooling and maintainance |
| B. | wear and tear |
| C. | additional parasitic losses |
| D. | all of the mentioned |
| Answer» E. | |
| 5. |
Field winding of a dc machine _________ |
| A. | always absorbs power |
| B. | absorbs real power at lagging load |
| C. | delivers power while behaving as generator |
| D. | always delivers power |
| Answer» B. absorbs real power at lagging load | |