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?
1. | the potential difference between the plates decreases \(K\) times. |
2. | the energy stored in the capacitor decreases \(K\) times. |
3. | the change in energy stored is \(\frac{1}{2}CV^{2}\left ( \frac{1}{K} -1\right )\) |
4. | the charge on the capacitor is not conserved. |
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: