An ideal gas is made to expand isothermally from $\;V_{1}\;$ to $\;V_{2}\;$ & is then compressed adiabatically to $\;V_{1}\;$ . Then the total work done is -

Question

$(a)\;positive\qquad(b)\;negative\qquad(c)\;zero\qquad(d)\;can't\;say$

Answer 1

Answer : (b) negative

Explanation :

The above graph depicts the process of expansion & compression . Since , for an adiabatic process the slope is $\;r(=\large\frac{Cp}{w})\;$ times the slope incase of isothermal process ,

$|w_{2}| > |w_{1}|$

So , the compressive work is more .

Total work done = |w_{1}|-|w_{2}| < 0