An insulated piston–cylinder device contains 2.5 l of saturated liquid water at a constant pressure of 175 kpa. water is stirred by a paddle wheel while a current of 8 a flows for 45 min through a resistor placed in the water. one-half of the liquid is evaporated during this constant-pressure process and the paddle-wheel work amounts to 400 kj, determine the voltage of the source. also, show the process on a p-v diagram with respect to saturation lines.