A cylinder with adiabatic walls is closed at both ends and is divided into two compartments by a frictionless adiabatic piston. Ideal gas is filled in both (left and right) the compartments at same P, V, T. Heating is started from left side until pressure changes to 27P8. If initial volume of each compartment was 9 litres then the final volume in right-hand side compartment is litres. (for this ideal gas CP/CV=1.5)
- 3
- 4
- 14
- 9
Answer
(2) 4
Solution
∵ The walls and the piston are adiabatic, no heat reaches the right-hand gas; the piston compresses it slowly ⇒ adiabatic process, PV = constant with =1.5
Frictionless piston ⇒ final pressure on the right = 27P8
P(9)1.5= 27P8 VR1.5
⇒ VR3/2= 827 (9)3/2= 827 27=8
∴ VR=82/3=4 litres
Answer: (2)