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 gas column before and after expansion respectively, T₁/T₂ then given by
 

• A

  ${\left(\frac{{\mathrm{L}}_1}{{\mathrm{L}}_2}\right)}^{\raisebox{1ex}{$2$}\!\left/ \!\raisebox{-1ex}{$3$}\right.}$

• B

  $\frac{{\mathrm{L}}_1}{{\mathrm{L}}_2}$

• C

  $\frac{{\mathrm{L}}_2}{{\mathrm{L}}_1}$

• D

  ${\left(\frac{{\mathrm{L}}_2}{{\mathrm{L}}_1}\right)}^{\raisebox{1ex}{$2$}\!\left/ \!\raisebox{-1ex}{$3$}\right.}$