# Mechanical Engineering - Thermodynamics - Discussion

Discussion Forum : Thermodynamics - Section 1 (Q.No. 5)
5.
There is a loss of heat in an irreversible process.
True
False
Explanation:
No answer description is available. Let's discuss.
Discussion:
40 comments Page 1 of 4.

Jithindas said:   4 years ago
During this transformation, there will be some heat energy loss or dissipation due to intermolecular friction and collisions. This energy will not be recoverable if the process is reversed.
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Mohit said:   5 years ago
Heat transfer through a finite temperature gradient leads to irreversibility. But there is no heat loss.

Another example is irreverible adiabatic process. NO heat loss is there. I think the Answer should be B.
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Anonymous said:   6 years ago
An irreversible process is always accompanied by an increase in entropy. This will result in heat loss.

Even in the case of the adiabatic irreversible process though there is no heat loss due to external irreversibility,

But internal irreversibility will lead to heat loss.
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NACHIMUTHU said:   6 years ago
Reversible process are cv, cp, ct process.

Irreversible process are throttling process and free expansion process.
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Chandrasekhar said:   7 years ago
In thermodynamics, reversible process is know as quize static process. Irreversible process means we can't get the same amount of energy when we reverse the process.

K.Nikhil said:   7 years ago
In thermodynamics, reversible process is know as quize static process. Irreversible process means we can't get the same amount of energy when we reverse the process. So amount of heat loses through the surroundings.

Adarsh Mishra said:   7 years ago
Every spontaneous process is irreversible (flowing water stream across finite potential difference) but there is no loss of HEAT.

All irreversible process are accompanied by loss of EXERGY (availability) instead.

Hemesh Kumar said:   8 years ago
1. If we want without any loss (heat) process then it will only reversible process which is a very slow process.

2. We can understand it by taking the example of piston-cylinder arrangement. In this according to irreversible process piston move in a cylinder with some speed, if speed I'd high than heat is a loss, therefore, it is an irreversible process and due to irreversible heat is lost.

On the other hand, heat is not lost when the process is very slow means one stroke of the piston is done in like one hour, one day, one month which is useless for any mechanism.

Hemesh Kumar said:   8 years ago
An irreversible process is a non-quasistatic process which is a fast process in comparison to quasistatic process and the fast process has affected the surrounding around them means loses some energy in the form of friction or heat or in any other type.

For ex- wheel of automobile release some energy on the road (surrounding) in the form of friction and heat which is useless after reaching in the surrounding.

Except Carnot cycle, every process is losses heat or energy without any loss no real process exists in nature.
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Pritam said:   8 years ago
According to inequality of Clausius.

dq/dt < 0 for irreversible process.

This shows that change in heat is always negative i.e. heat loss in the irreversible process.