Illustrate differences between an isothermal irreversible process and a reversible process by using a P-V diagram, and explain why Q might not be zero even when temperature is a constant
Illustrate differences between an isothermal irreversible process and a reversible process by using a P-V diagram,...
In thermodynamics, what is the difference between a reversible and irreversible isothermal expansion/compression? Also, I'm confused when the question gives a certain process to be irreversible/reversible, what hint is it talking about? (like which variable becomes constant?)
An internally reversible, externally irreversible process Ammonia in a piston-cylinder that maintains constant P is at 20°C, 1600 kPa and is now heated to 60°C in an internally reversible process. The external heat source is at a constant 70°C. We want to find the specific heat transfer in the process and the external (total) specific entropy generation.
Consider a reversible isothermal expansion of a gas at temperature τ from volume V to volume V + ∆V . This is not a monatomic ideal gas, but the internal energy of the gas is given by U(τ, V ) = a*V* τ^ 4 , where a is a constant. The pressure is p = (1/3 U)/V . (a) What is the change of energy of the gas in the expansion? (b) How much work is done on the gas...
Consider a reversible isobaric process from state I (P, Vi , Ti) to state II (P, Vf , Tf ), which we call “path I”. The “path I” is a single step process and, therefore, pressure is held constant during the entire process. “Path II”, on the other hand, is also isobaric overall, but involves two steps: reversible isochore (step 1) + reversible isothermal (step 2): (Ti , Vi) → (Tf , Vi) → (Tf , Vf ). Assume that...
11. A reversible heat engine uses a three-step cycle consisting of an isothermal expansion at temperature Ti, a constant volume cooling to temperature T2, and adiabatic compression back to the initial state. (a) Sketch the P-V diagram (b) If 1 mole of a van der Waals gas is used the working material, the efficiency of this engine is defined to be E = Suppose that the heat capacity of gas is independent of temperature. Show that the efficiency of the...
b) Figure Q1(b) shows a P-v diagram consists of isentropic, polytropic, and isothermal compression processes between the same pressure limits. Based on the figure, distinguish the work input to the compressor for all the three processes. (6 marks) PA -Isentropic (n = k) -Polytropic (1 <n<k) Isothermal (n = 1) Pi 1 V Figure Q1(b)
b) Figure Q1(b) shows a P-v diagram consists of isentropic, polytropic, and isothermal compression processes between the same pressure limits. Based on the figure, distinguish the work input to the compressor for all the three processes. (6 marks) PA -Isentropic (n = k) -Polytropic (1 <n<k) Isothermal (n = 1) Pi 1 V Figure Q1(b)
Using the isothermal transformation diagram for an alloy steel (type 4340) specify the nature of the final microstructure (in terms of micro-constituents present and approximate percentages) of a small specimen that has been subjected to the following time-temperature treatments: In each case assume that the specimen begins at 760°C and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenite structure. (a) (a) Rapidly cool to 400°C, hold for 10 seconds, and...
(3). A sample of 1.00 mol ideal gas molecules with Cp, m = 7/2 R is initially at p = 1.00 bar and V = 22.44 L and then put thought the following cycle in reversible processes: (a) constant-pressure expansion to twice its initial volume, (b) constant-volume cooling to its initial temperature, (c) isothermal-compression back to 1.00 bar. Calculate q, w, ΔU, ΔH, ΔS for each process and for the whole cycle.
7) An ideal gas is taken around the cycle shown in this p-V diagram, from a to b to c and back to a. Process b-c is isothermal. For process a- b, D. 0-0, AU<0 8) An ideal gas is compressed in a well-insulated chamber using a well-insulated piston. This process IS A) isochoric. B) isothermal. C) adiabatic. D) isobaric. 9) The process shown in the T-V diagram in the figure is an T. A) adiabatic compression. B) isothermal compression....