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Questions tagged [adiabatic]

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

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199 views

Rigorous Laughlin pumping argument

Is there a way to justify formally the Laughlin pumping argument? It is often argued that the spectral flow of Landau levels while varying the flux inserted through the Corbino ring should account for ...
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1answer
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Maximum velocity of piston pushed by a gas on adiabatic irreversible expansion [closed]

I am currently studying for my country's IPhO selection process and thermodynamics has to be one of my favorites right now. However I came across a very odd problem that is making me revise a lot of ...
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Can the ideal gas expand adiabatically and irreversely?

Suppose that the ideal gas is expanding adiabatically from the state $(P_1, V_1, T_1)$ to the state $(P_2, V_2, T_2)$ I think this process can be allowed to happen reversibly or irreversibly, but ...
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459 views

Entropy change in a reversible adiabatic expansion of ideal gas

Below is P-V curves of 1 mole of ideal gase for temperature 700K, 500K and 300K each. Now I would like to calculate entropy change of the system along the path from (1) to (3), which is adiabatic ...
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Adiabatic processes

Adiabatic process is a process that involves no interactions other than work. What I interpret from this is that change in energy = change in work done. however it is not the case but it’s the ...
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magnetic refrigeration and adiabatic processes

Suppose we have a magnetic material that is well insulated from its environment, and we then ramp up the current in a helmholtz coil that encloses the magnet. We then observe an increase in the magnet'...
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2answers
1k views

Adiabatic reversible and irreversible process

If I have 2 gases $A$ and $B$ which are at an initial state ($P_1$,$V_1$,$T_1$) and one gas say $A$ is taken through a reversible adiabatic process and the other gas $B$ through an irreversible ...
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251 views

Can steam freeze via adiabatic expansion?

Context: At the end of animation movie Steamboy, a huge steam engine's pressure vessel breaks, which results in the escaped steam freezing to ice. I've been thinking about this -- is it really ...
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Question about adiabatic process (in Landau&Lifshitz's book)

In section 11 of Landau's statistical physics part 1, he wrote the following: Let us suppose that a body is thermally isolated, and is subject to external conditions which vary sufficiently slowly. ...
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2answers
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Adiabatic expansion and first law

So I wanted to know whether the following equation would be correct for an adiabatic process. **adiabatic expansion ** ∆U = -W Adiabatic compression ∆U = W
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1answer
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End expansion point on overheated Rankine cycle

In an overheated Rankine cycle, the end point of the adiabatic expansion could end inside the dual-phase bell, or on the right. In the first case, the end expansion point falls of course on the ...
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ideal gas adiabatic process

I know how it is derived and here is my concern: $dU=-dA=-d(pV)$ p is not a constant here, it depends on V. So my logic says, ...
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1answer
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Explanation of the diabatic basis

In Curl Wittig's paper, (J. Phys. Chem. B 2005, 109,8428-8430) on the Landau Zener formula, he defines something called the "diabatic basis" for a wavefunction describing a two state system? What is ...
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488 views

adiabatic work done by gas

Suppose we have an adiabatic box with a fixed volume $V$ and contains $n_0$ mol of gas at pressure $p_0$ and temperature $T_0$. Now the box is punctured by a small hole and gas from the outside flows ...
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Transitionless quantum driving for specific eigenstates

Transitionless quantum driving is a concept that was invented by Berry in 2009. In his article on transitionless quantum driving he showed that it is possible to speed up adiabatic evolution of ...
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1answer
247 views

Why doesn't reversible adiabatic expansion generate heat?

In analogy to a compressed gas allowed to reversibly expand and do work, I've been thinking about the behavior of a compressed spring that is very slowly and incrementally relieved of its pressure. ...
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224 views

Adiabatic expansion of ideal gas

I am considering a system with initial pressure $P_{A}$ and volume $V_{A}$. The internal energy $U_{A}$ should be zero. Then I have the following law for an ideal mono atomic gas $P^{3}V^{5}=const$. ...
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2answers
1k views

When is an adiabatic process reversible?

Throughout my physics education this far, I have always understood that adiabatic expansions and compressions involving ideal gases are reversible and follow $pV^\gamma = $ constant, provided the ...
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1answer
168 views

Thermodynamic process in auto-refrigeration

I'm trying to understand why a high-pressure liquid drops in temperature when it's pressure is reduced in a refrigeration cycle. I can't use PV=nRT which only applies to gases, but a lower pressure ...
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258 views

Speed of a process in thermodynamics

As per my understanding, all adiabatic processes carried out in absence of an adiabatic wall need to be fast enough so that there is no heat exchange with the surrounding. Similarly, all isothermal ...
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3answers
455 views

Isothermal and Adiabatic Compression in the Carnot Cycle

I am reading about the Carnot Engine and I understood the first 2 stages (Isothermal and Adiabatic Expansion) well. In the 3rd stage where isothermal compression takes place, the surroundings do work ...
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1answer
654 views

Work done in adiabatic process irreversible and reversible

Work done for adiabatic reversible process is $(P1V1 - P2V2)/(γ-1)$ but this is also the work done for adiabatic irreversible process. How?
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106 views

Why can the equation of adiabatic process $P_1 V_1^\gamma=P_2 V_2^\gamma$ be written as $\Delta P/P=-\gamma \Delta V/V$?

Why can the equation of adiabatic process $P_1 V_1^\gamma=P_2 V_2^\gamma$ be written as $$\frac{\Delta P}{P}=-\gamma \frac{\Delta V}{V},$$ where $P_2-\Delta P=P_1$ and $V_2+\Delta V=V_1$ as in ...
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2answers
427 views

What causes adiabatic expansion?

What creates the force in the adiabatic system to expand the piston in the Carnot engine to move up without any changes in the thermodynamical factors? Can you please tell me what causes it?
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Shockwaves speed through rarer and denser atmosphere

I was going through the different speed of sound through different atmospheric/air conditions and the Newton-Laplace equation gives $ c=\sqrt{\frac{\gamma P}{\rho}} $ So, where does the ...
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1answer
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Calculation of adiabatic expansion using partial derivatives

Let's consider a gas for now (since we can generalise this result to other systems trivially). I want to calculate the change in temperature when the gas expands adiabatically. I am taught that I ...
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2answers
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Two gases separated by a movable piston in a cylindrical container

I want to ask about this problem: We have a cylinder compartment separated by a fixed piston in the middle. In the left volume we have a gas with pressure $P_L = P_0$ and on the right volume the same ...
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1answer
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Is my interpretation of how a Carnot Cycle works correct?

I'm trying to understand how the Carnot cycle works in my learning of it. Here's what I so far believe is what is happening: (A $\to$ B) A cylinder of gas is connected to a frictionless piston, and ...
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1answer
739 views

Steeper p v curve in adiabatic process

We know,in adiabatic process,the p v curve in indicator diagram is steeper than that of isothermal process.It indicates,in adiabatic process high change in pressure causes small change in volume ...
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Adiabatic volume change of an ideal gas thought process

I am struggling with trying to solve the following problem, attempting just (a) and the first part of (b) for this exercise: During a reversible adiabatic volume change of an ideal gas, $PV^{\gamma}...
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1answer
765 views

Plotting a $PV$ diagram for free expansion — why is it undefined?

Apparently trying to plot a $PV$ diagram for an adiabatic free expansion of ideal gas is undefined. I'm taking issue as to why this is the case. From what I understand using my diagram attached as my ...
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Why is $C_v$ used in the derivation of the adiabatic equation? [duplicate]

For any adiabatic process $P$,$V$ and $T$ change while $dQ=0$. By first law of thermodynamics, $$dQ=dU+dW$$ That is, it becomes $$dU+dW=0$$ At this stage, we set $$dU=C_v dT$$ Any further ...
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1answer
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Different ways to perform an adiabatic expansion

In this Wikipedia article https://en.wikipedia.org/wiki/Joule_expansion#Entropy_production, three ways to perform an adiabatic expansion are mentioned. Irreversible non-quasistatic Irreversible ...
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Difference between Adiabatic and Isothermal

I feel a little bit dumb asking this, but what's the difference between Adiabatic and Isothermal? Isothermal means: keeping constant temperature Adiabatic means: No heat leaving or entering system ...
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2answers
371 views

Can phase change/transition occur during adiabatic free expansion?

If I am not mistaken, during phase change/transition the internal energy is also changing, but for adiabatic free expansion the change in internal energy is zero. So if phase change can occur during ...
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What's the evolution of a state under an adiabatic evolution? [duplicate]

For an initial state $|\Psi\rangle_0$ as the ground state of a Hamiltonian $H(0)$, if it undergoes an adiabatic evolution $H(t)$ to reach the ground state $|\Psi\rangle_1$ of $H(1)$. Then what's the ...
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1answer
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Difference Between Adiabatic and Superconducting Quantum Computing

Wikipedia (not the most stringent source, I know) has separate pages for adiabatic and superconducting quantum computing. It's my understanding that all superconducting quantum computers are adiabatic ...
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1answer
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How much hotter will a compressed gas be than non-compressed?

Ok here is the scenario, I have an empty cup and a piston that forms an airtight seal. The gas in side is just standard air, at 14.7 psi, and 25ºC. If I compress the piston by 50% so the volume the of ...
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2answers
217 views

Two gases seperated by semi-permeable membrane

The problem is as follows: Two ideal gases are contained adiabatically and separated by an insulating, fixed piston that blocks the molecules of gas 2 but allows the molecules of gas 1 through(in both ...
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Is an isentropic process reversible?

In one of my books, a process is said to be isentropic from which they conclude that it is adiabatic thus reversible. I don't think "isentropic" is a sufficient condition for these conclusions. Can ...
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Does the temperature of a real gas decrease in the adiabatic free expansion?

The internal energy $U$ of a given mass of a real gas can be regarded as a function of temperature and volume i.e., $U(T,V)$. Under adiabatic free expansion, the change in the internal energy is zero ...
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Why do not we store energy with Adiabatic process?

Theoretically, if we have system like this and we put it inside Cryogenic storage dewar (thermos) that energy does not go outside we can store any amount of energy and we can get it back, when we ...
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How does adiabatic cooling make a nebula colder than the CMB?

According to measurements, the gas from the Boomerang Nebula is expanding so fast that it's colder than the cosmic microwave background radiation... how does such a simple mechanic work on such a ...
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364 views

Where does the energy come from for adiabatic processes of a Carnot cycle?

I'm getting stuck on where this additional energy comes to move the piston further outward/inward during adiabatic processes when the only energy changed is during isothermal processes. Can someone ...
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1answer
417 views

Constant Heat capacities during a quasi-static adiabatic expansion

How to prove the work done by an ideal gas with constant heat capacities during a quasi-static adiabatic expansion is equal to W=-C(Ti-Tf). I know we can use 1st law thermodynamic, Q=U-W where, Q = ...
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Where is wrong in the derivation about adiabatic theorem

There is a homework in Quantum Mechanics which is about adiabatic theorem. Let us argue where is wrong in following derivation. $$i \partial_t |\psi(t)\rangle = H(t) |\psi (t)\rangle \tag{1}$$ if $\...
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The graph (for ideal gas) between(-T)(dV/dP) and (V^2) for adiabatic process is? [closed]

Where P stands for Pressure, V is Volume and T is temperature. Please explain me from the beginning.
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Geometric phase and energy eigenstates in QM

In the section "Geometric phase" in the text "Introduction to Quantum Mechanics" by Griffiths page 379, he states $\psi_{n}(t)$ depends on $t$ because there is some parameter $R(t)$ in the Hamiltonian ...
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Queries of proof of adiabatic theorem in QM

I have a few questions regarding the proof of the adiabatic theorem in the book "Introduction to Quantum Mechanics" by Griffiths: The assumptions are that if the Hamiltonian changes with time then ...
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Why is $PV^\gamma$ constant in an adiabatic process?

In non isolated systems where there is no adiabatic process, $PV$ is constant. But the graph gets steeper in adiabatic process because of the $\gamma$ over the $V$. Why is it there in adiabatic ...