A \(12\) pF capacitor is connected to a \(50\) V battery. How much electrostatic energy is stored in the capacitor?
1. \(3.1\times10^{-8}\) J
2. \(2.9\times10^{-8}\) J
3. \(3.3\times10^{-8}\) J
4. \(1.5\times10^{-8}\) J

A parallel plate air capacitor of capacitance \(C\) is connected to a cell of emf \(V\) and then disconnected from it. A dielectric slab of dielectric constant \(K,\) which can just fill the air gap of the capacitor is now inserted in it. Which of the following is incorrect?

A capacitor of \(2~\mu\text{F}\) is charged as shown in the figure. When the switch \({S}\) is turned to position \(2,\), the percentage of its stored energy dissipated is:

       

1. \(20\%\)
2. \(75\%\)
3. \(80\%\)
4. \(0\%\)