With reference to solar water pumps
With reference to solar water pumps, consider the following statements:
- Solar power can be used for running surface pumps and not for submersible Pumps.
- Solar power can be used for running centrifugal pumps and not the ones with piston.
Which of the statements given above is/are correct?
- 1 only
- 2 only
- Both 1 and 2
- Neither 1 nor 2
Answer: D
Explanation
Solar water pumps are specially designed to utilize DC electric power from photovoltaic modules. The pumps must work during low light conditions, when power is reduced, without stalling or overheating. Low volume pumps use positive displacement (volumetric) mechanisms which seal water in cavities and force it upward. Lift capacity is maintained even while pumping slowly.
These mechanisms include diaphragm, vane and piston pumps. These differ from a conventional centrifugal pump that needs to spin fast to work efficiently. Centrifugal pumps are used where higher volumes are required. So statement 2 is not correct.
A surface pump is one that is mounted at ground level. Surface pumps work well when they draw water through suction less than 10 or 20 feet. A submersible pump is one that is lowered into the water. Most deep wells use submersible pumps. And both are compatible with the photovoltaic array (For Solar power). So statement 1 is not correct.
- Exam Year: 2020