Superheated steam at 700 kPa, 220 °C in a steam chest is expanded through a nozzle to a final pressure of 20 kPa. The throat diameter is 10mm. Assuming the expansion process to be isentropic and in equilibrium throughout, determine (a) the mass flow rate, (b) the exit velocity, (c) the dryness fraction at the exit and (c) the exit diameter.