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Questions tagged [adiabatic]

Thermodynamic processes that occur without exchanging heat between the system and its environment.

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Understanding adiabatic expansion

I need to understand a concept, which is Adiabatic expansion. I know that this process is where no heat exchange happens. Now, can i say that when an ideal gas undergoes an adiabatic expansion,then ...
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Change of entropy in irreverisle adiabatic expansion

For an irreversible and adiabatic expansion, I understood how calculate the entropy change to the system by using hypothetical path(reversible adiabatic process and isobaric process) But, I don't ...
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Adiabatic free expansion of real (Van der Waal's model) gas below/at/above inversion temperature

For free expansion, $W = 0$ And for an adiabatic process, $\Delta Q = 0$ Therefore, by the equation of the first law of thermodynamics, $\Delta U = 0$ For the Van der Waal model of a real gas, $\...
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Relation of tunneling and adiabatic quantum computation

This is a post-question of Question about tunneling diagram in adiabatic quantum computation. Since adiabatic quantum computation essentially tries to evolve the system by keeping it on the ground ...
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How is ideal gas law applicable to real gas?

I read one of the questions here on physics.stack exchange proving how the speed of sound increases with temperature using ideal gas law equation and adiabatic index. Here's the link: How can the ...
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295 views

Gas behaviour - compression

I have read that the slow compression of a gas results in an increase in its temperature. Is it essential that the gas be compressed slowly? What happens if the gas is compresses quickly?
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Energy Level Change in Adiabatic Reversible Process

I am currently trying to get my head around the concept of entropy. One way to understand it is that it can be related to the number of available energy levels in a system. From what I read, the ...
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Adiabatic fluctuations

In Baumann's cosmology lecture,http://www.damtp.cam.ac.uk/user/db275/Cosmology/Chapter4.pdf , chapter 4, page 89, he defines adiabatic perturbation as: Adiabatic perturbations have the property ...
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Gas turns into a vapour liquid mixture when it is adiabatically expands

Why does gas turn into a vapour liquid mixture when it is adiabatically expanded in a refrigerator?
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Rise in tempature in adiabatic process

I have some small problems with understanding increased tempature due to adiabatic prosesses. For instance, if you have a pump and pump air into a tire, the tempature within the pump will rise. This ...
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No temperature change during diabatic expansion? [closed]

So, checking some exercises from previous exams of where i study at, there is an exercise that goes like this (copying only the relevant stuff): A mole of a diatomic ideal gas expands from A to B ...
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Ideal Gas/Internal Energy/Adiabatic process Classical Thermodynamics

In an ideal gas case where $U=U(T)$ (i.e. internal energy depends only on temperature) and an adiabatic process takes place (1->2). Is it reasonable to assume that $T_1>T_2$ means $U(T_1)>U(...
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How does the state variables $(P,V)$ remain constant for a system with adiabatic wall

I have been very confused regarding how my physics textbook differentiates b/w an adiabatic wall and a diathermic wall. The term ‘equilibrium’ in thermodynamics appears in a different context : we ...
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Adiabatic Quantum Computing: why not just set the system in its problem Hamiltonian $H_{P}$ immediately?

Background: In any adiabatic quantum computer (AQC) algorithm, we solve problems in the following manner: We have an initial Hamiltonian, $H_{0}$, whose ground state is easy to find, and a problem ...
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Ground states being superposition states in adiabatic quantum computation

In Adiabatic Quantum Computing, a Hamiltonian $H$ is evolved for time $T$ according to $$H(t) = (1-t/T)H_{0} + (t/T)H_{P} $$ where $H_{0}$ is an initial Hamiltonian, and the ground state of $H_{P}$ ...
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Is it possible to increase the temperature of an ideal gas in an adiabatic sealed container with a frictionless piston for a lid?

As far as I understand it, if I pumped the piston repeatedly, compressing the gas, the temperature would go up for a second, but the minute I released the piston the higher pressure inside the ...
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Is reversible adiabatic process possible?

Is it possible to have reversible adiabatic process in practical? because if it is a reversible process than we allowing it to exchange heat with surroundings. If it is in insulation than either we ...
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Phase-shifting of instantaneous eigenstates in the adiabatic approximation

In my book Quantum Mechanics by B.H. Bransden and C.J. Joachain, there is a chapter on the adiabatic approximation. Here, the authors assume that the time-dependent Hamiltonian $\hat{H}(t)$ changes ...
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Work done in adiabatic process

When we try to establish a relation between the pressure and temperature in adiabatic process we come across a equation.. $dU = dq - PdV$ $dq=0$ (Adiabatic process) and, $dU=C_v.dT$ (Heat capacity ...
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Understanding why $\int_{T_1}^{T_2}C_Vd\ln(T) + \int_{V_1}^{V_2} nRd\ln(V) = 0$ is violated when $T_2$ and $V_2$ are picked

In Chapter 4 of Chemical Thermodynamics, by Peter A. Rock published by Oxford University Press, 1983, the author is trying to explain why a new state function is needed, specifically a state function ...
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How much heat it needs to be applyed to water to boil? [closed]

There is a mass of $2kg$of water, it needs to be boiled, then how much energy needs to be supplied? Mass of water $2 kg$ Initial temperature $20 C$ Final temperature $94 C$ $C_p$ $4.186\frac{KJ}{kgC}$...
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Why is $C_{V}$ allowed in this equation $\Delta E_{int} = nC_{V}\Delta T$ for an adiabatic process?

Since in an adiabatic process volume and pressure are changing I don't get how it's valid to use $C_{V}$ since that's the molar specific heat at constant volume. I must be missing something. Thanks!
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Difference between reversible and irreversible adiabatic process in PV diagram

let's say we've got a carnot-cycle in a pressure volume diagram with the following processes: 1 -> 2: reversible isothermal 2 -> 3: reversible adiabatic 3 -> 4: reversible isothermal 4 -> 1: ...
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Adiabatic theorem - quantum mechanics and thermodynamics [duplicate]

A diabatic process is defined as follows: Rapidly changing conditions prevent the system from adapting its configuration during the process, hence the spatial probability density remains unchanged. ...
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Entropy for irreversible adiabatic process

For an adiabatic process we know $dQ=0$. So the entropy change should also be zero. Please explain how can we calculate the entropy change.
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Is the adiabatic theorem in Quantum mechanics valid in general for Non-Hermitian Hamiltonians?

Is the adiabatic theorem in Quantum mechanics valid in general for Non-Hermitian Hamiltonians? The proofs I have come across for adiabatic theorem all assume at some point in the proof that the ...
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Derivation of $(\partial S/\partial X)_{E}+(\partial S/\partial E)_{X}f=0$ in Chandler's Statistical mechanics book

I am having trouble understanding something very introductory in Chandler's statistical mechanics book regarding the derivation of $(\partial S/\partial X)_{E}+(\partial S/\partial E)_{X}f=0$ The ...
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V versus P in an Adiabatic Process

I have a question in which a gas undergoes a an expansion in such a way that the Pressure is a linear function of the volume on a V versus P diagram. One of the professors I asked said that means an ...
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Change in temperature during adiabatic increase of pressure

Let us consider a system with a certain volume $V$ and at a particular temperature $T_0$. Suppose further that the pressure is increased adiabatically from $P_0$ to $P_1$. I want to be able to ...
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Does internal energy U always depend on temperature T?

One thermodynamic identity is $\mathrm dU=T~\mathrm dS-p~\mathrm dV + (\mu~\mathrm dN+\ldots)$. For a system of ferroelectric particles, which exhibit electric polarisation $P$ when exposed ...
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Can the average temperature increase in a closed adiabatic (isolated) system?

Assume a closed and adiabatic (isolated) system (no energy or mass transfer at the boundaries) then is it possible for the average temperature to change (increase or decrease)? Corollary: 1. If yes ...
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Importance of energy relation in Landau & Lifschitz “Statistical Physics”?

At the end of section 11 in "Statistical Physics" by Landau & Lifschitz, a supposedly important equation is derived. ... Comparing (11.1) with (11.2) we find: $$\frac{\overline{\partial ...
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Are all reversible processes adiabatic?

My understanding is that in a reversible process there is no increase in entropy, it remains constant. So $\Delta S = 0$ no? And since it's reversible we know from the second law that $\Delta S = \...
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Is there a prohibited region in $P-V$ plane?

Polytropic process generalize the particular thermodynamic processes with $$P V^{n}= \mathrm{constant}$$ Where, if $n$ changes, the curve on $P-V$ plane changes, as shown in the diagram. The orange ...
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Ground state of an adiabatic Hamiltonian as an eigenstate of the total spin

I am going through Quantum Adiabatic Evolution Algorithms with Different Paths by Farhi et al. Here, the authors propose to add a special term to the adiabatic Hamiltonian so that the path of the ...
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Does “IF isentropic THEN reversible” only holds for adiabatic processes?

I know that: IF adiabatic and reversible THEN isentropic First question: does the implication IF isentropic THEN reversible hold for adiabatic processes? Second Question: if yes to the above, are ...
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Adiabatic piston: why is Callen's argument flawed?

This question is related to this one. I would ask you to read that question and my answer to the question itself before answering this one. The problem is the following. In his book Thermodynamics, ...
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Slowly Varying Functions for Adiabatic Invariants - The Same as Karamata's?

In section 49 (and 50) of Landau and Lifschitz's "Classical Mechanics", adiabatic invariants are discussed, which are related to functions which vary adiabatically or "slowly" with time. Admittedly ...
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Two rising bubbles of differing temperatures

Consider two bubbles rising through some medium (water, for example). Given that the two bubbles have the same initial size, pressure, and temperature but differing velocities, which bubble will be ...
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Are there any specific examples of the application of Lewis-Riesenfeld procedure to time dependent Hamiltonians in QM?

Lewis-Riesenfeld invariant theory is a theory applicable to solve time-dependent Schrodinger equations. I have always encountered the theory related to the procedure, however never encountered any ...
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585 views

Free Expansion Of and Ideal Gas

We know that in free expansion of an ideal gas, no heat enters or leaves the system. We also know that $P_\text{initial}V_\text{initial}=P_\text{final}V_\text{final}$ is valid. If heat exchange ...
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Condition for adiabatic approximation, derivation?

In quantum mechanics it is said that an adiabatic approximation is valid when $$T\gg \frac{\hbar}{\Delta E},$$ where $T$ is the time scale of variation of the Hamiltonian and $\Delta E$ is the typical ...
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Adiabatic expansion on $(P,T)$ diagram

Consider a certain substance which is described by pressure $P$, volume $V$ and temperature $T$. In one thermodynamics exercise I was asked to draw one adiabatic expansion from $V_1$ to $V_2$ in a $(P,...
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Entropy generation during irreversible adiabatic expansion

During irreversible adiabatic expansion entropy is generated. It means that the gas expands to as greater volume than that during reversible adiabatic expansion for the same change in pressure. How ...
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Why are sound waves adiabatic?

I want to know why we can treat sound waves as an adiabatic process. Precisely, I know that pressure and density vibrations occur so fast that molecules have no time to exchange energy (I might be ...
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Change in entropy of two isolated systems merged into one system

From Statistical Physics, 2nd Edition by F. Mandl: Two vessels contain the same number $N$ molecules of the same perfect gas. Initially the two vessels are isolated from each other, the gases being ...
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Difference between throtling and adiabatic expansion

Throttling process is an isoenthalpic process.$$U+PV=constant.$$ during throttling process does the gas do work at the cost of internal energy such that its temperature decreases? Then what is the ...
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Simplest Live Demonstration of Adiabatic Transport

I have to give a presentation on Berry phase. I would like to give the simplest live demonstration of adiabatic transport. If I move an object in a loop and return that object back into its original ...
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Relation between Pressure and volume in adiabatic process?

Why in adiabatic compression and expansion small volumetric change occurs while in isothermic compression or expansion very small pressure is applied and volume changes very significantly i am ...
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832 views

Adiabatic compression and expansion and isothermal expansion? [closed]

Please help me in understanding the concepts Why in adiabatic compression and expansion small volumetric change occurs while in isothermic compression or expansion very small pressure is applied and ...