Thermodynamics: Practice Problem & Solution
Assertion (A): If heat is supplied to an ideal gas in an isothermal process, the internal energy of the gas increases. Reason (R): When an ideal gas expands adiabatically, it does positive work and its internal energy increases.
Solution Explained:
To solve this problem, we apply the core principles of Thermodynamics. Understanding the underlying formula is key to arriving at the correct answer below:
For an ideal gas in an isothermal process, temperature is constant, so internal energy \(Delta U = 0\). Thus (A) is false. In adiabatic expansion, work \(W > 0\) is done by the gas and heat \(Q = 0\), so \(Delta U = -W < 0\), meaning internal energy decreases. Thus (R) is false. Both (A) and (R) are false.
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