Q: In a process on a system, the initial pressure and volume are equal to the final pressure and volume
(i) The initial temperature must be equal to the final temperature
(ii) The initial internal energy must be equal to the final internal energy
(iii) The net heat given to the system in the process must be zero
(iv) The net work done by the system in the process must be zero
(a)(i) , (ii)
(b) (ii) , (iii)
(c) (iii) , (iv)
(d) (i) , (iv)
Sol:(a) Number of moles , n = PV/RT = constant (for given mass of gas)
P1 V1 = P2 V2
i.e., T1 = T2
U1 = U2
In cyclic process, initial and final thermodynamic variables are same, ∆U = 0
∆Q = ∆W ≠ 0