Q: In a given process on an ideal gas , dW = 0 and dQ < 0 . Then for the gas
(a) the temperature will decreases
(b) the volume will increases
(c) the pressure will remain constant
(c) the temperature will increases
Ans: (a)
Sol: According to First Law of Thermodynamics ,
dQ = dU + dW
dW = 0
⇒ dQ = dU = n CV dT
dQ < 0
i.e., n CV dT < 0 i.e., temperature falls