During adiabatic expansion internal energy decreases by 2J, then work done in this process is:
Correct answer: A. 2J
- A. 2J
- B. 1J
- C. -1J
- D. -2J
Explanation
The work done during adiabatic expansion can be calculated using the First Law of Thermodynamics, which states that the change in internal energy (ΔU) is equal to the heat added to the system (Q) minus the work done by the system (W). Since this is an adiabatic process, there is no heat added or removed from the system (Q=0). Therefore, ΔU = -2 J (as the internal energy decreases by 2J).Thus, W = -ΔU = -(-2 J) = 2 J. The rest options have incorrect values
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About First Law of Thermodynamics
The first law relates heat supplied, work done and the change in internal energy through energy conservation. Problems use sign conventions and apply the law to isothermal, adiabatic, isobaric and isochoric processes. Internal energy is a state function, while heat and work depend on the path followed.
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