If the plates were small, they would both become charged almost instantly, attaining a relative voltage equal to the voltage of the battery. Figure 11-2 is a relative graph showing the in­tensity of the electric field between the plates as a function of time elapsed from the in­stant the plates are connected to the battery terminals. Still, it will then discharge slowly over time as the energy stored in the capacitor is dissipated through the resistor. This reaction showed that some of the electricity from the machine had been stored. They discovered that electricity obtained from an electrostatic machine could be stored for a period of time and then released. The energy stored in a capacitor can provide a quick burst of power to a circuit or smooth out variations in a power supply. The capacitance of a capacitor can be tuned by selecting different dielectric materials, changing the geometry of the conductive plates, or adding additional plates in parallel. The time constant of the circuit, which describes the rate at which the capacitor charges and discharges, is determined by the product of the resistance and capacitance of the circuit. But because the plates are gigantic, it will take a while for the negative one to "fill up" with electrons, and it will take an equal amount of time for the other one to get electrons "sucked out." Finally, however, the volt­age between the two plates will be equal to the battery voltage, and an electric field will exist in the space between the plates.