1. A plate capacitor (filled with air) has a voltage of 5 V when charged to 80 mC. It is then charged some more to a new voltage of 12 V. What is its new charge?
The same capacitor is left connected to the 12 V voltage source, but a material with a dielectric constant of 4 is inserted between its plates. What is its new charge?
2. A 0.209 F capacitor is desired. What area must the plates have if they are to be separated by a 2.07 mm air gap?