In arid and semi arid regions, ground water considers the major source for drinking and other uses, due to the shortage of rainfall and lack of surface water. Pumps are the suitable tools of lifting water from, the ground basins and wells, but, centrifugal pumps are the proper types for doing this job, because of their high pressures and velocities. Therefore, it is necessary to study its characteristics, specially design, speed, discharge and efficiency. But the development of its science and technology, play major role for simulation in the laboratory within short time, instead of using field works and other conventional methods. In addition to that, theoretical analysis and experimental investigation are proper ways of getting optimum use and benefits, by using computer technique and sophisticated equipments for input, analysis and output data in real and precise results. Therefore, this study was a proper way of comparing model and prototype for two cases; constant and variable voltages. Further more, the different apparatus combined with computer software were able to give general description and deep analysis.