6) A mole of monatomic gas initially at 0.83 atm and in thermal contact with the surroundings at 294 K undergoes a reversible isothermal expansion to a new pressure of 0.7 atm. Then it is put in contact with a cold reservoir at 273K, and cooled to 273 K, while the volume is held constant (isochoric cooling). Then it is reversibly and isothermally compressed at 273 K to its original volume, at which point it is placed in contact with the surroundings at 294 and heated at constant volume until the temperature returns to 294 K. Calculate AU ,Q, and W for each of the four stages, and the ratio of the net work for a cycle to the heat absorbed from the hot reservoir. How does the efficiency compare to the efficiency of a Carnot engine operating between the same two temperatures?

6) A mole of monatomic gas initially at 0.83 atm and in thermal contact with the surroundings at 294 K undergoes a reversible isothermal expansion to a new pressure of 0.7 atm. Then it is put in contact with a cold reservoir at 273K, and cooled to 273 K, while the volume is held constant (isochoric cooling). Then it is reversibly and isothermally compressed at 273 K to its original volume, at which point it is placed in contact with the surroundings at 294 and heated at constant volume until the temperature returns to 294 K. Calculate AU ,Q, and W for each of the four stages, and the ratio of the net work for a cycle to the heat absorbed from the hot reservoir. How does the efficiency compare to the efficiency of a Carnot engine operating between the same two temperatures?

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

Give only typing answer with explanation and conclusion Water vapor enters a continuous flow adiabatic turbine at 10 MPa pressure, 450°C temperature and 80 m/s velocity, and exits at 50 m/s velocity at 10 kPa pressure and 92 percent dryness. What is the enthalpy of the water vapor at the turbine inlet, in kJ/kg?
50 grams of water at 20ºC is converted into steam at 250ºC at constant atmospheric pressure. Assuming the heat capacity per gram of liquid water to remain constant at 4.2 J/g K and the heat of vaporization at 100ºC to be 226 J/g, and using Cp/R=a+bT+cT2, calculate the entropy change of the system. a=3.652, b=1.157x10-3 K-1, c=0.142x10-6 K-2
A 1.5-dm3 sample of hydrogen gas is initially at 3.0 bar pressure and 25.0 °C, which can be regarded to be ideal. It is reversibly and adiabatically enlarged until the volume reaches 5.0 dm3. The heat capacity of H2 is 28.80 J K^–1 mol^–1 and is believed to be temperature independent. a. Calculate the gas's final pressure and temperature after it has expanded. b. Calculate the process's ΔU and ΔH.
Example 7. A stream of 2 m3/s of outdoor air at 4°C dry-bulb temperature and 2°C thermodynamic wet-bulb temperature is adiabatically mixed with 6.25 m3/s of recirculated air at 25°C dry-bulb temperature and 50% rh. Find the dry-bulb temperature and thermodynamic wet-bulb temperature of the resulting mixture.
0.03 m3 of nitrogen contained in a cylinder behind apiston is initially at 1.05 bar and 15ºC. The gas iscompressed isothermally and reversibly until the pressureis 4.2 bar. Calculate the change of entropy, the heat flow,and the work done, and sketch the process on a p-v andT-s diagrams. Assume nitrogen to act as a perfect gas.Molecular weight of nitrogen = 28.
A frictionless piston-cylinder device contains a saturated liquid-vapor mixture of water at 400K. During a constant pressure, process, 960 kJ of heat is transferred to the surrounding air at 300K. As a result, part of the water vapor contained in the cylinder condenses. Determine the entropy change of the water in kJ/K.
2 moles of an ideal gas with a fixed volume of molar heat capacity of 12.54 J / mol K are rapidly expanded adiabatically against a constant external pressure of 106 N / m2 before 300 K and 2x106 N / m2; then the initial state is restored by adiabatic reversible and isothermal reversible compression, respectively. Calculate and summarize the values of Q, W, ∆U and ∆H for each step and cycle. Explain the 1st Law of Thermodynamics with the terms state function and Path Function and interpret it using the values you find for the cycle (R: 8.314 J / mol K).
A frictionless piston-cylinder device contains a saturated liquid-vapor mixture of water at 400K. During a constant pressure, process, 960 kJ of heat is transferred to the surrounding air at 300K. As a result, part of the water vapor contained in the cylinder condenses. Determine the entropy change of the surrounding air in kJ/K.
An ideal gas at an initial state of 4.1, atm.38°C is expandedirreversibly to a final state of 2 atm, 4.4oCAssuming the specific heats of the gas to be C= 0.5150 and Cv= 0.3098 kJ/kg-°K calculate the change in entropy.
A container filled with 45 kg of liquid water at 95°C is placed in a 90-m3 room that is initially at 12°C. Thermal equilibrium is established after a while as a result of heat transfer between the water and the air in the room. Using constant specific heats, determine the entropy generation. Assume the room is well sealed and heavily insulated.
A certain water heater operates under steady flow conditions receiving 3.78 kg/s of water at temperature 74oC and enthalpy of 309.7 KJ/kg. The water is heated at temperature 102oC and enthalpy of 2679.2 KJ/kg. The mixture leaves the heater as liquid water at temperature 100oC, enthalpy 419.04 KJ/kg. How many kg per hour of steam must be supplied to the heater?
Calculate the change of entropy(a) of a bath containing water, initially at 20 ◦ C,when it is placed in thermal contact with a verylarge heat reservoir at 80 ◦ C,(b) of the reservoir when process (a) occurs,(c) of the bath and of the reservoir if the bath isbrought to 80 ◦ C through the operation of a Carnotengine between them.The bath and its contents have total heat capacity10^4 J/K .