Question

Work done for the process A$\to$ B shown in the figure is

• A. $1\text{J}$
• B. $1.5\text{J}$
• C. $4.5\text{J}$
• D. $0.3\text{J}$

Answer 1

The correct option is D $0.3\text{J}$

From the data given in the question
Pressure at state $A$ is $\left(P_1\right)=10\text{kPa}$
Pressure at state $B$ is $\left(P_2\right)=30\text{kPa}$
Volume at state $A$ is $\left(V_1\right)=10\times {10}^{-6}{\text{m}}^2$
Volume at state $B$ is $\left(V_2\right)=25\times {10}^{-6}{\text{m}}^2$
We know that, area under P - V curve with V-axis gives work done by the system.


Area under graph as shown in figure = Area of trapezium.
Thus,
Workdone $\left(W\right)=\frac{1}{2}(P_1+P_2)(V_2-V_1)$
$=\frac{1}{2}\times (30+10)\times {10}^3\times (25-10)\times {10}^{-6}$
Workdone $\left(W\right)=0.3\text{J}$
Thus, option (d) is the correct answer.