MCQOPTIONS
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MCQOPTIONS
This section includes 10 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. |
THE_PITCH_FACTOR,_IN_ROTATING_ELECTRICAL_MACHINERY,_IS_DEFINED_AS_THE_RATIO_OF_RESULTANT_EMF_OF_A?$ |
| A. | full-pitched coil to that of a chorded coil |
| B. | full-pitched coil to the phase EMF |
| C. | chorded coil to the phase EMF |
| D. | chorded coil to that of a full-pitched coil |
| Answer» E. | |
| 2. |
A_FRACTION_PITCH_WINDING_IS_USED_TO_REDUCE?$ |
| A. | amount of copper in the winding |
| B. | size of the machine |
| C. | harmonics in the generated EMF |
| D. | cost of the machine |
| Answer» E. | |
| 3. |
If a stator has 48 slots, 6 poles and 3 phase with narrow spread winding, then the third harmonic belt factor is ___________? |
| A. | 0.9556 |
| B. | 0.6407 |
| C. | 0.1944 |
| D. | None of the mentioned |
| Answer» C. 0.1944 | |
| 4. |
A 3-phase machine has integral slot winding with fundamental distribution factor kd1, the distribution factor for nth harmonic kdn is ____________ |
| A. | less than k<sub>d<sub>1</sub></sub> |
| B. | more than k<sub>d<sub>1</sub></sub> |
| C. | equal to k<sub>d<sub>1</sub></sub> |
| D. | depends upon the number of slots and poles |
| Answer» B. more than k<sub>d<sub>1</sub></sub> | |
| 5. |
The armature winding of a 2-pole, 3-phase alternator for each phase is distributed in a number of slots per phase. The RMS value of the voltage per phase is less than the RMS value of the voltage per coil multiplied by the number of coils in series because the |
| A. | RMS value of the voltage in different coils of the phase is different |
| B. | equal RMS voltages in different coils of the phase has mutual phase difference |
| C. | maximum value of the induced voltage in different coils of the phase are different |
| D. | different coils of the phase pass through different saturated regions of the magnetic circuit |
| Answer» C. maximum value of the induced voltage in different coils of the phase are different | |
| 6. |
The belt factor is defined as the ratio of |
| A. | arithmetic sum of coil EMF to the phasor sum of coil EMFs |
| B. | phasor sum of EMF per coil to the arithmetic sum of EMF per coil |
| C. | phasor sum of coil EMFs to the arithmetic sum of coil EMFs |
| D. | phasor sum of coil EMFs to per phase voltage |
| Answer» D. phasor sum of coil EMFs to per phase voltage | |
| 7. |
In a machine with coil span 9, if a coil has its one coil-side in slot 1, then its other coil-side must be in ____________ |
| A. | slot 9 |
| B. | slot 8 |
| C. | slot 10 |
| D. | slot 2 |
| Answer» D. slot 2 | |
| 8. |
What is the coil span for a 2 pole 18 slot machine? |
| A. | 9 |
| B. | 4.5 |
| C. | 18 |
| D. | 6 |
| Answer» B. 4.5 | |
| 9. |
Consider the following statements regarding the design of distributed armature winding in a 3-phase alternator: |
| A. | it reduces the phase-belt harmonics |
| B. | it increases the utilization of the armature iron and copper |
| C. | it increases rigidity and mechanical strength of the winding |
| D. | it reduces copper in the overhang of the winding |
| Answer» D. it reduces copper in the overhang of the winding | |
| 10. |
The angular slot pitch, γ is given by |
| A. | γ= πP/Total number of slots Elect radians |
| B. | γ= 180P/Total number of slots Elect degrees |
| C. | γ= 180/Slots per pole Elect degrees |
| D. | Any of the mentioned |
| Answer» E. | |