question_answer 18)

                  An ideal gas undergoes isothermal process from some initial state \[i\] to final state f. Choose the correct alternatives.                 (a) \[dU=0\]                 (b) \[dQ=0\]                 (c) \[dQ=dU\]               (d) \[dQ=dW\]                

Answer:

                  (a, d) During isothermal process, temperature remains constant. Hence, change in internal energy is zero i.e. \[=dU=0\].                 Also \[d\theta \,=dU+\,dW\] (Ist law of Thermodynamics)