Charge meter: Easy way to measure charge and capacitance some interesting electrostatic experiments

A simple and inexpensive method of building a charge meter is discussed and as an application two experiments are suggested. A charge meter can be used for identification and measurement of charges on dielectric media such as teflon, nylon, silk and rubber balloon obtained by method of friction. Teflon and rubber balloon are found to be negatively charged while silk and nylon are found to be positively charged. A charge meter can also be used to measure capacitance of parallel plate capacitors and hence calculate dielectric constant of the medium between its plates. The values of dielectric constant of transparency plastic sheet and plain paper so obtained are 2.71 ± 0.08 and 4.8 ± 0.29. In the last part, the effective capacitance of a capacitor obtained by placing paper and transparency plastic sheet placed one above the other is shown to be equivalent to a series combination of individual paper and transparency plastic sheet capacitors. These experiments can be pedagogical tools for teaching electrostatics.