Saturated steam vapor is contained in a piston–cylinder device. While heat is added to the steam, the piston is held stationary, and the pressure and temperature become 1.2 MPa and 700°C, respectively. Additional heat is added to the steam until the temperature rises to 1200°C, and the piston moves to maintain a constant pressure.
1. The initial pressure of the steam is most nearly
(a) 250 kPa
(d) 1000 kPa
(b) 500 kPa
(e) 1250 kPa
(c) 750 kPa
2. The work done by the steam on the piston is most nearly
(a) 230 kJ/kg
(d) 2340 kJ/kg
(b) 1100 kJ/kg
(e) 840 kJ/kg
(c) 2140 kJ/kg
3. The total heat transferred to the steam is most nearly
(a) 230 kJ/kg
(d) 2340 kJ/kg
(b) 1100 kJ/kg
(e) 840 kJ/kg
(c) 2140 kJ/kg