In an adiabatic process,the initial and final temperatures of $1 \, mol$ of an ideal gas are $T_1$ and $T_2$ respectively. The change in internal energy of the gas is .......

$A$ triatomic gas at an initial temperature of $18^{\circ}C$ is compressed adiabatically to $1/8$ of its initial volume. What is the final temperature of the gas?

If $\Delta E_{int}$ represents the increase in internal energy and $W$ represents the work done by the system,which of the following statements is correct for a thermodynamic system?

$A$ monoatomic gas is stored in a thermally insulated container and the gas is suddenly compressed to $(\frac{1}{8})^{\text{th}}$ of its initial volume. The ratio of final pressure to initial pressure is (in $:1$)

The temperature of the system decreases in the process of

$A$ monoatomic ideal gas, initially at temperature $T_{1}$, is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature $T_{2}$ by releasing the piston suddenly. If $l_{1}$ and $l_{2}$ are the lengths of the gas column before and after the expansion respectively, then the value of $\frac{T_{1}}{T_{2}}$ will be