A cylinder of cross-section area A has two pistons of negligible mass separated by distances l loaded with spring negligible mass. An ideal gas at temperature T1 is in the cylinder where the springs are relaxed. When the gas is heated by some means its temperature becomes T2 and the springs get compressed by l2 each. If P0 is atmospheric pressure and spring constant k=2P0Al then the ratio of T2 and T1 is _______