One mole of an ideal gas at temperature T₁ expands according to the law (P/V) = constant. Find the work done when the final temperature becomes T₂ : 

R/2 (T₂ - T₁)

W = \(\int_{V_1}^{V_2} P dV\)

  = \(\int_{V_1}^{V_2} KV dV\) ... (\(\frac{P}{V} = constant = K\))

\(\Rightarrow W = \frac{1}{2} K (V_2^2 - V_1^2)\)

PV = RT

But, P = KV

KV² = RT

\(\Rightarrow K (V_2^2 - V_1^2) = R(T_2 - T_1)\)

\(\Rightarrow W = \frac{R}{2}(T_2 - T_1)\)