Water Analogy to Circuits

This web page will attempt to demonstrate an analogy between electrical currents and water currents. A pipe is analogous to a wire, charge is analogous to a volume of water, electric current is analogous to water flow, and voltage is analogous to water pressure. I would recommend that you start with resistors which are modeled with sand filters. Following this, a capacitor is modeled with a membrane and an inductor is modeled with a water wheel. Finally, a diode is modeled as a one-way valve.

I'd like to thank Kevin Luscott and David Nairn for their suggestions.

Once I finished this presentation, I discovered there was an excellent wikipedia page: Hydraulic analogy. I would recommend that any student read this page. There is a specific table on this page which associates the hydraulic, electric, and thermal models.

Warning: an analogy is just that, a means of allowing a person to think of a problem in terms of a simpler problem. Unfortunately, analogy can be taken too far and this will lead to erroneous conclusions. If you as a student continue to think about electric current as water current, you will will, after a while, start making incorrect assumptions. Do not ask if there is a water analogy for every electric circuit element.

References

• C.R. Nave, Water circuit analogy to electric circuit Part 1, HyperPhysics, Georgia State University, 2008.
• C.R. Nave, Water circuit analogy to electric circuit Part 2, HyperPhysics, Georgia State University, 2008.
• Wikipedia, Hydraulic analogy, 2009.
• Hallie Snowman et al., Water Analogy to Electric Circuits, Cornell University, 2006.

To Do

Add images showing equivalent circuits.

Let us associate a coulomb with with a L and therefore the volt would be associated with J/L. An ampere is associated with a L/s and an ohm (V/A) is therefore (J/L) / (L/s), a henry (Vs/A) is therefore (Js/L) / (L/s) and farads (As/V)...