Question

In a closed insulated container a liquid is stirred with a paddle to increase the temperature which of the following is true : -

• A. $\Delta E = W \neq 0 , q = 0$
• B. $\Delta E = W =q \neq 0$
• C. $\Delta E =0, W = q \neq 0$
• D. $W = 0 \, \Delta E = q \neq 0$

Answer 1

Answer: (A)

$\Delta E = W \neq 0 , q = 0$

Answer 2

In closed insulated container a liquid is stirred with a paddle to increase the temperature, therefore it behaves as adiabatic process, so, for it $q = 0$. Hence, from first law of thermodynamics
$\Delta E=q+W\,\,i\,\,f\,\,q = 0$
$\therefore \Delta E=W$ but not equal to zero.