Extracted text: A kalpan turbine develops 2250 kW under a net head of 5.5 m and with overall efficiency 87 percent. The "draft tube" has a diameter of 2.8 m at its inlet and has an efficiency of 78 percent. In order to avoid cavitation, the pressure head at entry to the draft tube must not drop more than 4.5 m below atmosphere. Calculate the maximum height at which the runner may be set above the tail race level.