• # question_answer A system changes from the state $({{P}_{1}},\,\,\,{{V}_{1}})$ to $({{P}_{2}},\,\,\,{{V}_{2}})$ as shown in the figure below. What is the work done by the system?                       A) $7.5\times {{10}^{5}}$ joule B) $7.5\times {{10}^{5}}$ ergs C) $12\times {{10}^{5}}$ joule D) $6\times {{10}^{5}}$ joule

[c] Work done = Area of graph ABD; From above we get, Area $=1/2\times 4(1\times {{10}^{5}}+5\times {{10}^{5}})$$=2\times 6\times {{10}^{5}}=12\times {{10}^{5}}\text{J}$.