ANALYSIS. The permittivity of free space decreases as the distance between the plates increases. Each dielectric that is a different material and is inserted between the parallel plates gives a different dielectric constant. Even when the capacitance of a capacitor is the same for capacitors in parallel and capacitors in series, the experimental equivalent capacitance comes out different. For parallel it is much higher than for series. Some percent error might have occurred due to discrepancies in the equipment and also when things were measured, they might have been off by just a bit