Advertisements
Advertisements
Question
Explain thermodynamics of the adiabatic process.
Advertisements
Solution
- An adiabatic process is a process during which there is no transfer of heat from or to the system.
- For adiabatic change, Q = 0.
∴ ΔU + W = 0
∴ ΔU = –W - This implies, for adiabatic expansion, W is positive and ΔU is negative i.e. when work is done by the system adiabatically its internal energy decreases.
- Similarly, when a system is compressed adiabatically, W is negative and ΔU is positive i.e., the internal energy of the system increases in an adiabatic compression.
- Heat transfer to and from the system is prevented by either perfectly insulating the system from its environment or by carrying out the change rapidly so that there is no time for any exchange of heat.
- The temperature of the system changes, i.e., ΔT ≠ 0
- Usually, it is a sudden change and the system does not find any time to exchange heat with its environment.
- p-V diagram for the adiabatic process is as shown below:
APPEARS IN
RELATED QUESTIONS
Answer in brief.
Why should a Carnot cycle have two isothermal two adiabatic processes?
An ideal gas is taken through an isothermal process. If it does 2000 J of work on its environment, how much heat is added to it?
Heating a gas in a constant volume container is an example of which process?
Draw a p-V diagram showing positive work with varying pressure.
Explain the cyclic process.
3 mole of a gas at temperature 400 K expands isothermally from an initial volume of 4 litres to a final volume of 8 litres. Find the work done by the gas. (R = 8.31 J mol-1 K-1)
Explain graphically (i) positive work with varying pressure, (ii) negative work with varying pressure, and (iii) positive work at constant pressure.
Write a note on free expansion.
Explain the thermodynamics of the isochoric process.
Give the equation of state for an isothermal process.
Apply first law for an isobaric process.
Give an equation state for an isochoric process.
Draw the PV diagram for the isothermal process.
Draw the PV diagram for the adiabatic process.
What is a cyclic process?
What are the limitations of the first law of thermodynamics?
In an adiabatic expansion of the air, the volume is increased by 4%, what is the percentage change in pressure? (For air γ = 1.4)
In a petrol engine, (internal combustion engine) air at atmospheric pressure and temperature of 20°C is compressed in the cylinder by the piston to `1/8` of its original volume. Calculate the temperature of the compressed air. (For air γ = 1.4)
An ideal gas is taken in a cyclic process as shown in the figure. Calculate
- work done by the gas
- work done on the gas
- Net work done in the process
Among the amount of heat absorbed and the amount of work done by a system, ______
One mole of an ideal gas with `gamma` = 1.4 is adiabatically compressed so that its temperature rises from 27° C to 47° C. The change in the internal energy of the gas is (R = 8.3 J/mol.K) ____________.
In which of the following processes, beat is neither absorbed nor released by a system?
An ideal gas A and a real gas B have their volumes increased from V to 2V under isothermal conditions. The increase in internal energy ____________.
An ideal gas is compressed to half its initial volume by means of several processes. Which of the process results in the maximum work done on the gas?
We consider a thermodynamic system. If `Delta"U"` represents the increase in its internal energy and W the work done by the system, which of the following statements is true?
The work done on the system in changing the state of a gas adiabatically from equilibrium state A to equilibrium state B is 22.4 J. If the gas is taken from state A to B through another process in which the net heat absorbed by the system is 15.5 cal, then the net work done by the system in the latter case is ______.
( l cal = 4.2 J)
Which of the following processes is reversible?
An ideal gas is taken through a cyclic process ABCDA as shown in figure. The net work done by the gas during the cycle is ______.
