MCQOPTIONS
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MCQOPTIONS
This section includes 22 Mcqs, each offering curated multiple-choice questions to sharpen your Design Electrical Machines knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What is the formula for the maximum air passing per second at maximum efficiency? |
| A. | maximum air passing = 2 * volume of air passing per second |
| B. | maximum air passing = volume of air passing per second |
| C. | maximum air passing = 2 / volume of air passing per second |
| D. | maximum air passing = volume of air passing per second / 2 |
| Answer» B. maximum air passing = volume of air passing per second | |
| 2. |
What is the formula for the area of outlet opening? |
| A. | area of outlet opening = maximum air passing per second / 0.42 * peripheral speed |
| B. | area of outlet opening = maximum air passing per second * 0.42 * peripheral speed |
| C. | area of outlet opening = maximum air passing per second * 0.42 / peripheral speed |
| D. | area of outlet opening = 1/maximum air passing per second * 0.42 * peripheral speed |
| Answer» B. area of outlet opening = maximum air passing per second * 0.42 * peripheral speed | |
| 3. |
What is the range of the difference of air temperature at inlet and outlet? |
| A. | 11-150C |
| B. | 10-130C |
| C. | 12-160C |
| D. | 14-180C |
| Answer» D. 14-180C | |
| 4. |
What is the formula for the volume of air? |
| A. | volume of air = 0.9 * losses in kW / difference of air temperature at inlet and outlet |
| B. | volume of air = 0.9 * losses in kW * difference of air temperature at inlet and outlet |
| C. | volume of air = 0.9 / losses in kW * difference of air temperature at inlet and outlet |
| D. | volume of air = 1 / 0.9 * losses in kW * difference of air temperature at inlet and outlet |
| Answer» B. volume of air = 0.9 * losses in kW * difference of air temperature at inlet and outlet | |
| 5. |
How many steps are required in the design of the fan? |
| A. | 7 |
| B. | 8 |
| C. | 9 |
| D. | 6 |
| Answer» B. 8 | |
| 6. |
What is the range of the coefficients of hydrodynamic resistances for the rounded edges at inlet? |
| A. | 12-20 * 10-3 |
| B. | 10-20 * 10-3 |
| C. | 15-20 * 10-3 |
| D. | 12-30 * 10-3 |
| Answer» B. 10-20 * 10-3 | |
| 7. |
What is the range of the coefficients of hydrodynamic resistances for the rectangular edges at inlet? |
| A. | 10-20 * 10-3 |
| B. | 30 * 10-3 |
| C. | 20-30 * 10-3 |
| D. | 20-25 * 10-3 |
| Answer» C. 20-30 * 10-3 | |
| 8. |
What are the ventilating parts in the ventilating circuits?a) sharp or projecting inlet edgesb) inlet cornersc) variations in cross-sections of air pathsd) sharp or projecting inlet edges, inlet corners, variations in cross-sections of air paths 4.What is the range of the coefficients of hydrodynamic resistances for the protruding edges at inlet? |
| A. | sharp or projecting inlet edgesb) inlet cornersc) variations in cross-sections of air pathsd) sharp or projecting inlet edges, inlet corners, variations in cross-sections of air paths 4.What is the range of the coefficients of hydrodynamic resistances for the protruding edges at inlet?a) 40-50 * 10-3 |
| B. | inlet cornersc) variations in cross-sections of air pathsd) sharp or projecting inlet edges, inlet corners, variations in cross-sections of air paths 4.What is the range of the coefficients of hydrodynamic resistances for the protruding edges at inlet?a) 40-50 * 10-3b) 40-60 * 10-3 |
| C. | variations in cross-sections of air pathsd) sharp or projecting inlet edges, inlet corners, variations in cross-sections of air paths 4.What is the range of the coefficients of hydrodynamic resistances for the protruding edges at inlet?a) 40-50 * 10-3b) 40-60 * 10-3c) 30-50 * 10-3 |
| D. | sharp or projecting inlet edges, inlet corners, variations in cross-sections of air paths 4.What is the range of the coefficients of hydrodynamic resistances for the protruding edges at inlet?a) 40-50 * 10-3b) 40-60 * 10-3c) 30-50 * 10-3d) 30-40 * 10-3View Answer |
| Answer» E. | |
| 9. |
What is the formula for the fundamental relationship for the design of the ventilation system? |
| A. | head of air inside the machine = hydrodynamic resistance * volume of air passing2 |
| B. | head of air inside the machine = hydrodynamic resistance + volume of air passing2 |
| C. | head of air inside the machine = hydrodynamic resistance – volume of air passing2 |
| D. | head of air inside the machine = hydrodynamic resistance / volume of air passing2 |
| Answer» B. head of air inside the machine = hydrodynamic resistance + volume of air passing2 | |
| 10. |
HOW_MANY_STEPS_ARE_REQUIRED_IN_THE_DESIGN_OF_THE_FAN??$ |
| A. | 7 |
| B. | 8 |
| C. | 9 |
| D. | 6 |
| Answer» B. 8 | |
| 11. |
What is the range of the difference of air temperature at inlet and outlet?$ |
| A. | 11-15<sup>0</sup>C |
| B. | 10-13<sup>0</sup>C |
| C. | 12-16<sup>0</sup>C |
| D. | 14-18<sup>0</sup>C |
| Answer» D. 14-18<sup>0</sup>C | |
| 12. |
What_is_the_formula_for_the_volume_of_air?$ |
| A. | volume of air = 0.9 * losses in kW / difference of air temperature at inlet and outlet |
| B. | volume of air = 0.9 * losses in kW * difference of air temperature at inlet and outlet |
| C. | volume of air = 0.9 / losses in kW * difference of air temperature at inlet and outlet |
| D. | volume of air = 1 / 0.9 * losses in kW * difference of air temperature at inlet and outlet |
| Answer» B. volume of air = 0.9 * losses in kW * difference of air temperature at inlet and outlet | |
| 13. |
What is the formula for the maximum air passing per second at maximum efficiency ? |
| A. | maximum air passing = 2 * volume of air passing per second |
| B. | maximum air passing = volume of air passing per second |
| C. | maximum air passing = 2 / volume of air passing per second |
| D. | maximum air passing = volume of air passing per second / 2 |
| Answer» B. maximum air passing = volume of air passing per second | |
| 14. |
What is the formula for the number of blades? |
| A. | number of blades = 3.14 * outside diameter * (1.25 – 1.5)* width of fan |
| B. | number of blades = 3.14 / outside diameter * (1.25 – 1.5)* width of fan |
| C. | number of blades = 3.14 * outside diameter / (1.25 – 1.5)* width of fan |
| D. | number of blades = 3.14 * outside diameter * (1.25 – 1.5) / width of fan |
| Answer» D. number of blades = 3.14 * outside diameter * (1.25 ‚Äö√Ñ√∂‚àö√ë‚àö¬® 1.5) / width of fan | |
| 15. |
What is the formula of the width of fan? |
| A. | width of fan = area of outlet opening * 2.88 * outside diameter */ coefficient of utilization |
| B. | width of fan = 1/ area of outlet opening * 2.88 * outside diameter * coefficient of utilization |
| C. | width of fan = area of outlet opening * 2.88 * outside diameter * coefficient of utilization |
| D. | width of fan = area of outlet opening / 2.88 * outside diameter * coefficient of utilization |
| Answer» E. | |
| 16. |
What_is_the_formula_for_the_area_of_outlet_opening? |
| A. | area of outlet opening = maximum air passing per second / 0.42 * peripheral speed |
| B. | area of outlet opening = maximum air passing per second * 0.42 * peripheral speed |
| C. | area of outlet opening = maximum air passing per second * 0.42 / peripheral speed |
| D. | area of outlet opening = 1/maximum air passing per second * 0.42 * peripheral speed |
| Answer» B. area of outlet opening = maximum air passing per second * 0.42 * peripheral speed | |
| 17. |
How many data are required for the design of fan? |
| A. | 3 |
| B. | 4 |
| C. | 5 |
| D. | 6 |
| Answer» D. 6 | |
| 18. |
What factor/factors are required to evaluate the hydrodynamic resistance? |
| A. | area of cross section |
| B. | hydrodynamic coefficients |
| C. | area of cross section or hydrodynamic coefficients |
| D. | area of cross section and hydrodynamic coefficients |
| Answer» E. | |
| 19. |
What is the range of the coefficients of hydrodynamic resistances for the protruding edges at inlet? |
| A. | 40-50 * 10<sup>-3</sup> |
| B. | 40-60 * 10<sup>-3</sup> |
| C. | 30-50 * 10<sup>-3</sup> |
| D. | 30-40 * 10<sup>-3</sup> |
| Answer» C. 30-50 * 10<sup>-3</sup> | |
| 20. |
What are the ventilating parts in the ventilating circuits? |
| A. | sharp or projecting inlet edges |
| B. | inlet corners |
| C. | variations in cross-sections of air paths |
| D. | sharp or projecting inlet edges, inlet corners, variations in cross-sections of air paths |
| Answer» E. | |
| 21. |
What is the formula for the total head produced? |
| A. | total head produced = ‚àë coefficient of hydrodynamic resistance + volume of air passing per second2 |
| B. | total head produced = ∑ coefficient of hydrodynamic resistance – volume of air passing per second2 |
| C. | total head produced = ‚àë coefficient of hydrodynamic resistance * volume of air passing per second2 |
| D. | total head produced = ‚àë coefficient of hydrodynamic resistance / volume of air passing per second2 |
| Answer» D. total head produced = ‚Äö√Ñ√∂‚àö‚Ć‚àö¬¥ coefficient of hydrodynamic resistance / volume of air passing per second2 | |
| 22. |
What is the formula for the fundamental relationship for the design of ventilation system? |
| A. | head of air inside the machine = hydrodynamic resistance * volume of air passing2 |
| B. | head of air inside the machine = hydrodynamic resistance + volume of air passing2 |
| C. | head of air inside the machine = hydrodynamic resistance – volume of air passing2 |
| D. | head of air inside the machine = hydrodynamic resistance / volume of air passing2 |
| Answer» B. head of air inside the machine = hydrodynamic resistance + volume of air passing2 | |