In Figure 6 a gas turbine drives a 4-pole, three-phase alternator through a reduction gearbox. The alternator supplies 12 MW to the 50 Hz, 11 kV grid at 0.85 power factor lagging. Using the data on the figure, determine (a) the gear ratio (turbine speed : alternator speed), (b) the line current of the alternator (in amperes) and (c) the torque on the turbine shaft (in kN·m).