An insulated (adiabatic) piston-cylinder device contains 3l of saturated liquid water at a constant pressure of 150 kpa. the water is stirred by a paddle wheel. a power source supplies an electric current of 8 a for 30 mins to a heating resistor placed inside the water. one half of the liquid is evaporated during the constant-pressure process. the paddle wheel work amounts to 400 kj. what is the voltage of the power source? draw the pv diagram for the process. show the approximate location of the saturation curves. note: 1m^3=1000l and 1000va= 1kj/s