According to first law of thermodynamics, what is the relationship between the change in the internal energy of a closed system ΔU, the head added to the system (Q) and the work done by the system W.
Correct answer: B. ΔU=Q-W
- A. ΔU=Q+W
- B. ΔU=Q-W
- C. ΔU=Q*W
- D. ΔU=Q/W
Explanation
The first law of thermodynamics, also known as the law of energy conservation, states that the change in internal energy (ΔU) of a closed system is equal to the heat added to the system (Q) minus the work done by the system (W):ΔU = Q - WThis equation indicates that:- If heat is added to the system (Q > 0), the internal energy increases.- If work is done by the system (W > 0), the internal energy decreases.- If the system is adiabatic (Q = 0), the change in internal energy is equal to the negative of the work done
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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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