An electricity generating installation uses a francis turbine with a rotational speed of 1260 rpm. the net head across the turbine is 124m and the volume flow rate is 0.5 m3/s. the radius of the runner is 0.6 m, the height of the runner vanes at inlet is 0.03 m and the angle of the inlet guide vanes is set at 72â° from the radial direction. assuming that the absolute flow velocity is radial at exit, find the torque and power exerted by the water. calculate the hydraulic efficiency.