Q.12 A Francis turbine develops 3 MW under a head of 50 m at an overall efficiency of 88%. The diameter of the runner at the inlet is 80 cm and the runner rotates with 300 rpm. If the hydraulic efficiency of the turbine is 90% and the runner height at the inlet is 10 cm, calculate (a) the guide vane angle at the inlet (b) the blade angle at the inlet.