5. A monoatomic ideal gas, initially at temperature

T₁, is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature. T₂  by releasing the piston suddenly. If L₁ and L₂ are the lengths of the gas column before and after expansion respectively, then T₁/T₂ is given by

(a)     ( L₁/L₂)^2/3                       (b) L₁/L₂

(c)   L₂ /L₁                                 (d) (  L₂ /L₁ )^2/3

Ans. d