Charge and Discharge of Capasitors: Revisiting the Analogy with Water in Connected Containers

Abstract

Abstract Analogy can be considered as an approach in teaching an abstract concept, where in electricity related to capacitor, water and containers are sometimes used. In this work we try to summerize available reports related to this. Usually, the water flow (WF) represents electric current, water height (WH) is an analogy to electric potential difference, container floor area (FA) can be viewed as capacitance, hose (HS) is as connecting wire, and water reservoir with large floor area (WR) behaves as a battery. The voltage saturation while charging the capacitor and voltage decaying while discharging capacitor can be obtained with the use of WH, FA, HS, and WR elements. Even it is not so ideal, but the observation tends to show qualitatively similar curves. We also present comparation table between electric circuit and water circuit. Unfortunately, not every aspect in electric side has the counter part in the water side. The difference between the two systems are clear and must be noticed to avoid misconception for the teaching target.