A graph between Q(x-axis) and V(y-axis) is plotted for capacitors A and B.Here slope of B > slope of A.Which capacitor will have higher electrostatic energy stored in it ?
As E = ½ QV
Since they have a linear relationship ,when you plot the graph you can easily see by your self which ever plot has more area under the graph has more energy stored and if slope of B > slope of A. Then A will be having more area under the graph.