MCQOPTIONS
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MCQOPTIONS
This section includes 11 Mcqs, each offering curated multiple-choice questions to sharpen your Utilization Of Electrical Energy knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
One of the basic parameters used by ASME to define fans is: |
| A. | Specific ratio |
| B. | Impeller power |
| C. | Static fan efficiency |
| D. | Fan efficiency |
| Answer» B. Impeller power | |
| 2. |
A motor has to be selected for following load cycle. Load uniformly rising from zero to 100 hp in 10 minutes after which it is constant at 100 hp for the next 10 minutes, followed by no load period of 30 minutes. Suitable size of continuous rated motor is: |
| A. | 100 hp |
| B. | 25 hp |
| C. | 50 hp |
| D. | 200 hp |
| Answer» D. 200 hp | |
| 3. |
HP of fan/blower is proportional to _______, where N is speed. |
| A. | N |
| B. | N2 |
| C. | N3 |
| D. | √N |
| Answer» D. √N | |
| 4. |
An elevator drive is required to operate ______. |
| A. | Three quadrants |
| B. | Two quadrants |
| C. | All four quadrants |
| D. | One quadrant only |
| Answer» D. One quadrant only | |
| 5. |
In a blower fan, reducing the RPM by 10% |
| A. | decreases power requirement by 27% |
| B. | increases power requirement by 16% |
| C. | has no effect on power requirement |
| D. | None of the above |
| Answer» B. increases power requirement by 16% | |
| 6. |
In the case of centrifugal pumps, the starting torque compared to full load torque is approximately |
| A. | 10 per cent |
| B. | 100 per cent |
| C. | 20 per cent |
| D. | 50 per cent |
| Answer» B. 100 per cent | |
| 7. |
Axial flow fans are |
| A. | Tube axial |
| B. | Vane axial |
| C. | Propeller |
| D. | All of the above |
| Answer» E. | |
| 8. |
In fans, power (P) is related to speed (N) by relation |
| A. | P ∝ N |
| B. | P ∝ N2 |
| C. | P ∝ N3 |
| D. | None of the above |
| Answer» D. None of the above | |
| 9. |
An electric motor operates at full-load of 100 KW for 10 min, at 1 / 2 load for next 20 min, no-load for the next 20 min and this cycle repeats continuously. Find the continuous rating of the suitable motor. |
| A. | \(\sqrt {1000} \;kW\) |
| B. | \(\sqrt {300} \;kW\) |
| C. | \(\sqrt {3000} \;kW\) |
| D. | 75 kW |
| Answer» D. 75 kW | |
| 10. |
Power output of a fan is based on |
| A. | Fan volume and fan total pressure |
| B. | Air flow rate |
| C. | Air temperature |
| D. | All of the above |
| Answer» B. Air flow rate | |
| 11. |
Dynamic braking is very effective if the dc motor _________. |
| A. | is series excited |
| B. | is shunt excited |
| C. | is separately excited |
| D. | has cumulative compound excitation |
| Answer» D. has cumulative compound excitation | |