Question

For a given process on an ideal gas $dw=0$ and $dq=-ve$, then for the gas:

• A. the volume will decrease
• B. the pressure will remain constant
• C. the temperature will increase
• D. the temperature will decrease

Answer 1

Answer: (D)

the temperature will decrease

From the first law of thermodynamics

$\Delta U=q+W$

Here, dW=0

$\therefore \Delta U=dq$

But dq < 0

Hence, dU<0 i.e. -ve

Hence, the temperature will decrease.

Hence, the correct option is $\text{D}$