A piston-cylinder assembly has 1kg of R-134a at state 1 with 600 kPa, 110°C, and is then brought to saturated vapour, state 2, by cooling. The cooling continues to state 3 where the R-134a is saturated liquid. Find the work in each of the two steps, 1 to 2 and 2 to 3.

A piston-cylinder assembly has 1kg of R-134a at state 1 with 600 kPa,

1.	A piston-cylinder assembly has 1kg of R-134a at state 1 with 600 kPa, 110°C, and is then brought to saturated vapour, state 2, by cooling. The cooling continues to state 3 where the R-134a is saturated liquid. Find the work in each of the two steps, 1 to 2 and 2 to 3.
A.	0, -20.22 kJ
B.	-20.22 kJ,0
C.	0, 0
D.	-20.22 kJ, -20.22 kJ
Answer» B. -20.22 kJ,0

Discussion

No Comment Found

Related MCQs

A piston cylinder contains 3 kg of air at 20°C and 300 kPa. It is now heated at a constant pressure to 600 K. Find the work in the process.
A piston/cylinder contains 1 kg water at 20°C with volume 0.1 m3. While the water is heated to saturated vapour, the piston is not allowed to move. Find the final temperature.
A piston/cylinder has 5m of liquid 20°C water on top of piston with cross-sectional area of 0.1 m2. Air is let in under the piston that rises and pushes the water out. Find the necessary work to push all the water out.
A piston cylinder contains air at 600 kPa, 290 K and volume of 0.01 m3. A constant pressure process gives out 54 kJ of work. Find the final temperature of the air.
A constant pressure piston cylinder contains 0.2 kg water in the form of saturated vapour at 400 kPa. It is now cooled to occupy half the original volume. Find the work in the process.
A piston-cylinder contains 0.1 kg saturated liquid and vapour water at 100 kPa with quality 25%. The mass of the piston is such that a pressure of 500 kPa will float it. The water is heated to 300°C. Find the work.
Ammonia at 10°C with a mass of 10 kg is in a piston-cylinder arrangement with an initial volume of 1 m3. The piston initially resting on the stops has a mass such that a pressure of 900 kPa will float it. The ammonia is now slowly heated to 50°C. Find the work in the process.
10 kg of water in a piston-cylinder exists as saturated liquid/vapour at 100 kPa, with a quality of 50%. It is now heated till the volume triples. The mass of the piston is such that a cylinder pressure of 200kPa will float it. Find the work given out by the water.
A piston-cylinder contains 1 kg of liquid water at 300 kPa, 20°C. Initially the piston floats, with a maximum enclosed volume of 0.002 m3 if the piston touches the stops. Now heat is added so that the final pressure is 600 kPa. Find the work in the process.
Ammonia in a piston/cylinder arrangement is at 80°C, 700 kPa. It is now cooled at constant pressure to saturated vapour (state 2) at which point the piston is locked with a pin. The cooling continues to −10°C (state 3). Find the work.

A piston-cylinder assembly has 1kg of R-134a at state 1 with 600 kPa, 110°C, and is then brought to saturated vapour, state 2, by cooling. The cooling continues to state 3 where the R-134a is saturated liquid. Find the work in each of the two steps, 1 to 2 and 2 to 3.

Discussion

No Comment Found

Related MCQs

Reply to Comment