What is change in internal energy if a system gains xJ of heat and yJ work is done on it?
What is change in internal energy if a system gains xJ of heat and yJ work is done on it?
- x - y
- - x + y
- - x - y
- x + y
The Correct Option is A
Solution and Explanation
The change in internal energy (ΔU) of a system can be determined using the first law of thermodynamics, which states that the change in internal energy is equal to the heat (Q) added to the system minus the work (W) done by the system:
ΔU = Q - W
In this case, the system gains xJ of heat (Q = xJ), and yJ of work is done on it (W = yJ).
Substituting these values into the equation, we have:
ΔU = xJ - yJ
Simplifying further, we get:
ΔU = (x - y)J
Therefore, the correct option is (A) x - y.
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