what is the difference between adiabatic and isothermal process??

which process is mostly used and greater feasibility?

  • Mohit Kumar Kushwah
  • 08 Nov
  • 17 Answers

17 Answers
  • adiabatic process means heat transfer during that process is zero, it can be achieved if process is very fast so that there is no time to heat exchange but practically it is ideal. where in case of isothermal process there is no change in internal energy as well as temperature it can achieved if process is too slow so that energy entering to system will completely transferred to surrounding.it is also an ideal process.

  • First answer to your specific doubt:
    1. How the heat content of the system will change if temperature is constant : To change heat content , necessary condition is that there should exist a temperature gradient. That is to say your system can remain at constant temperature and still reject/accept heat if your surrounding is at a different temperature. Example is melting of ice or boiling of water. Both process reject/accept heat at constant temperature. There is however a temperature difference between ice/water system and its surrounding.

    2. How the temperature of the system will change if heat content is constant : By work done on system. Hence temperature of system will change even if there is no heat content added or removed from system.

    Please understand temperature and heat are two very different concepts. 
    Temperature is a state property like pressure, volume , internal energy etc and is used as a variable to define state of a system.

    Heat is energy in transit which crosses boundary of system. It along with workwill drive changes in state properties like temperature. That is to say they together move  system from one state to another, according to the given definition of problem.

    Hence by definition of 
    Adiabatic : There is no heat transfer. Whatever work is done on system will drive change in state properties. Temperature being a state property may change and also pressure, specific volume , internal energy and other state properties as well.

    Isothermal : There is no change in Temperature. There is however no restriction on drivers of change i.e heat and work. They can take finite non zero values and will drive change in other state properties like pressure and volume but not temperature(because of definition of isothermal process, and such process are physical possible for example melting of ice as I mentioned in the beginning).

  • In contrast, an adiabatic process is where a system exchanges no heat with its surroundings (Q = 0). In other words, in an isothermal process, the value ΔT = 0 and therefore ΔU = 0 (only for an ideal gas) but Q ≠ 0, while in an adiabatic process, ΔT ≠ 0 but Q = 0.

  • In very laymen terms it can be told that isothermal is the process where WORK is done between the same temperature difference,whereas in adiabatic the work is done where there is NO heat or temperature difference is there . As according to first law (conservation of energy) where Heat is converted to work .

  • Adiabatic :- Adiabatic means there will be no heat transfer between system and surrounding. The entropy of the system will remain constant. Isothermal :- Isothermal means that the temperature will not change during the process. The practically desirable process for any work consuming or work producing device is Isothermal. Due to its high maintenance cost to run any process Isothermally we use Adiabatic in compressor or turbine.

  • In Isothermal process system exchange heat with surrounding, but in Adiabatic no exchange of heat, in Isothermal process temperature remains constant but in Adiabatic it may change

  • Adiabatic

  • adiabatic process: No transfer of heat and mass whereas isothermal: No change in temperature (heat may be added or removed eg. refrigerator, heat pump)

  • Adiabatic process is a non reversible constant enthalpy process meanwhile isothermal process is a constant temperature process. Speaking of comparing them in terms of feasibility then adiabatic process is not a hundred percent feasible because it will always follow some loss in the energy, energy is transferred from one point to another but that does not involve A Hundred Percent efficiency.

  • In the adiabatic process Q=0 while in the isothermal process∆T=0

  • In adiabatic process there is no heat transfer... Reversible adiabatic also called isentropic process...

  • In adiabatic process there is no heat transfer between the system and surroundings ideally.But in actual system  some heat transfer takes place.In isothermal process heat transfer takes place between the system and surroundings so that the temperature of the system is maintained constant.
    In actual work done in an Adiabatic process is greater than the isothermal process.So In maximum systems you will find Adiabatic process

  • adiabatic means neither gain of heat nor loss of heat between system and surrounding. Isothermal means temperature is constant.

  • ?????????? ????? ?? Q=0. ??? ???????? ?? T=0.???

  • Main diffrence is that isothermal process occurs under constant temperature whereas adiabetic process occurs under varying temperature.

  • in isothermal process temperature is constant and in ideal condition heat transfer is equal to work transfer
                      but in adiabatic pocess no heat transfer from system to surrounding and surrounding to system only work is transferred

  • Adiabatic is closed system process. Isothermal is at constant temperature

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