Question

In an adiabatic process, no transfer of heat takes place between system and surroundings. Choose the correct option for free expansion of an ideal gas under adiabatic condition from the following.

• A. $q =0, \Delta T \neq 0, w =0$
• B. $q \neq 0, \Delta T =0, w =0$
• C. $q =0, \Delta T =0, w =0$
• D. $q=0, \Delta T<0, w \neq 0$

Answer 1

Answer: (C)

$q =0, \Delta T =0, W =0$
For free expansion, $W =0$
For an adiabatic process, $q =0$
Therefore, from first law of thermodynamics,
$\Rightarrow $ Internal energy $(\Delta U )= q + W$
As $q$ and $W$, both are $o$,
$\therefore \Delta U = q + W =0+0=0$
As there is no change in internal energy, temperature will also remain constant.
$\therefore \Delta T =0$