In order to calculate the energy stored in a capacitor, we can use the formula below:
[tex]E=\frac{Q^2}{2C}[/tex]Where Q is the charge and C is the capacitance.
So, for Q = 40 * 10^-6 C and C = 6 * 10^-6 F, we have:
[tex]\begin{gathered} E=\frac{(40\cdot10^{-6})^2}{2\cdot6\cdot10^{-6}} \\ E=\frac{1600\cdot10^{-12}}{12\cdot10^{-6}} \\ E=133\cdot10^{-6}\text{ J} \\ E=133\text{ }\mu J \end{gathered}[/tex]Therefore the correct option is the fourth one.
