MCQOPTIONS
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MCQOPTIONS
This section includes 7 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 F1 is the constant amplitude of fundamental rotating MMF wave, the space harmonics of order 6K+1 (where K=1,2,3 .), the harmonic MMF wave is of _____________ |
| A. | Constant amplitude and stationary in space |
| B. | Constant amplitude and rotates along F<sub>1</sub> |
| C. | Varying amplitude and rotates along F<sub>1</sub> |
| D. | Constant amplitude and rotates against F<sub>1</sub> |
| Answer» C. Varying amplitude and rotates along F<sub>1</sub> | |
| 2. |
The amplitude of rotating MMF wave is proportional to ___________ |
| A. | N<sub>ph</sub> and P |
| B. | I and P |
| C. | N<sub>ph</sub> and I |
| D. | N<sub>ph</sub>, I and P |
| Answer» D. N<sub>ph</sub>, I and P | |
| 3. |
The magnitude of rotating flux _____________ at all instants of time. |
| A. | Changes |
| B. | Remains constant |
| C. | Pulsates |
| D. | Any of the mentioned |
| Answer» C. Pulsates | |
| 4. |
Which of the following statements are correct regarding individual phase MMF in rotating machines? |
| A. | It is a rotating MMF wave |
| B. | It is not a rotating MMF wave and its amplitude doesn t alternate along its own phase axis |
| C. | It is not a rotating MMF wave but its amplitude merely pulsates |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 5. |
If the phase sequence of supply currents are reversed, then the direction of rotation of the resultant MMF wave will ___________ |
| A. | Be reversed |
| B. | Remains unchanged |
| C. | Cannot be determined |
| D. | None of the mentioned |
| Answer» B. Remains unchanged | |
| 6. |
What is the amplitude of rotating MMF produced as a result of m-phase currents flowing in m-phase windings? (where Fm is maximum MMF in any one phase, when current is maximum in that phase.) |
| A. | (2/m)F<sub>m</sub> |
| B. | mF<sub>m</sub> |
| C. | (m/2)F<sub>m</sub> |
| D. | F<sub>m</sub> |
| Answer» D. F<sub>m</sub> | |
| 7. |
The speed at which rotating magnetic field revolves is called? |
| A. | Induction speed |
| B. | Synchronous speed |
| C. | Relative speed |
| D. | Rotating speed |
| Answer» C. Relative speed | |