# analogy between current flow and water flow

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As the back-pressure from the stretched rubber approaches the applied pressure, the current becomes less and less. The electric current used in homes and in most commerce is alternating current (AC), analogous to a flow of water in a pipe which rapidly sloshes back and forth. 1 0. charge Q is analogous to the number of cars. The mass and surface area of the wheel and its blades are analogous to inductance, and friction between its axle and the axle bearings corresponds to the resistance that accompanies any non-superconducting inductor.An alternative inductor model is simply a long pipe, perhaps coiled into a spiral for convenience. A pipe with flowing water is like a wire with flowing current, and a partial clog in the pipe is like a resistor in the circuit. 2 Answers. For some applications, the water analogy is … Thane Heins relates the advice of a professor "Our Motors and Generators Concepts professor in college always warned us students to stay away from the 'water' analogy which tends to lead us astray because it fails to take into account the magnetic field energy produced around all current bearing wires and especially the work this energy does when producing the counter-electromotive-torque/work produced inside all electric generators and the change in kinetic energy of the system this work performs when generators are placed on-load." The higher the pressure, the higher the flow, and vice-versa. For any circuit, fluid or electric, which has multiple branches and parallel elements, the flowrate through any cross-section must be the same. Drawing banks and pictures of cars is tedious, so as we continue, banks will be drawn using the battery symbol with the number of cells equal to the number of vaults. Fluid velocity and resistance of metals: As with water hoses, the carrier drift velocity in conductors is directly proportional to current. The electronic–hydraulic analogy (derisively referred to as the drain-pipe theory by Oliver Lodge)  is the most widely used analogy for "electron fluid" in a metal conductor. The animation was written by David M. Harrison in April 2003. Ohm’s Law also makes intuitive sense if you apply it to the water-and-pipe analogy. Resistance in most electrical conductors is a linear function: as current increases, voltage drop increases proportionally (Ohm's Law). There is a close analogy between charge flowing around an electrical circuit and water flowing through a set of pipes. After struggling to understand what each property of electric currents meant, I found an analogy that related electric current to water flow. The hydraulic analogy can give a mistaken sense of understanding that will be exposed once a detailed description of electrical circuit theory is required. Resistance: In the analogy, resistance is represented by rough (bumpy) road. Voltage is water pressure. Mechanical system. An ideal voltage source (ideal battery) or ideal current source is a dynamic pump with feedback control. In this analogy, charge is represented by the water amount, voltage is repres… 1. The flow of the heat from one body to another can be considered similar to the flow of current in a conductor. Hydraulic analogy with horizontal water flow. Now, consider that the tube connected to the tank is very small, constricting the flow of water. It also requires that the principles can be transferred to the target (electrical) system. 173-177. Voltage or current source:  A dynamic pump with feedback control. I would recommend that you start with resistors which are modeled with sand filters. A transistor is a valve in which a diaphragm, controlled by a low-current signal (either constant current for a BJT or constant pressure for a FET), moves a plunger which affects the current through another section of pipe. Water flowing through pipes is pretty good mechanical system that is a lot like an electrical circuit. CMOS is a combination of two MOSFET transistors. Hydraulic systems are deceptively simple: the phenomenon of pump cavitation is a known, complex problem that few people outside of the fluid power or irrigation industries would understand. Since electric current is invisible and the processes in play in electronics are often difficult to demonstrate, the various electronic components are represented by hydraulic equivalents. Current Law and Flowrate. Student Section – Water Analogy to Electric Circuits Flow rate (Current) in a Series Circuit The flow rate (current) of water through the circuit can be detected with the flow meter (ammeter), which turns faster for a higher flow rate and slower for a lower flow rate. Water-flow analogy. The Journal of the Acoustical Society of America 35.3 (2005): 326-338. , A slightly different paradigm is used in acoustics, where acoustic impedance is defined as a relationship between acoustic pressure and acoustic particle velocity. the flow of water the speed at which water flows the resistance to flow See answer sblackbear02 is waiting for your help. Two paradigms can be used to introduce the concept to students using pressure induced by gravity or by pumps. This is formalized in Kirchhoff's current law, which does not have an analogy to hydraulic systems, where the amount of the liquid is not usually constant. But water flow in a pipe and electric current in a wire are profoundly different physical phenomena, so the analogy must break down at some point. “The water in resovoirs A and B stands at different heights. Also, an accelerating electron will drag its neighbors along while attracting them, both because of magnetic forces. As described, the fluid flow conveys pressure fluctuations, but fluids do not reverse at high rates in hydraulic systems, which the above "low frequency" entry does accurately describe. In an analogy between water and electric current, water would correspond to charge. Answer to: In an analogy between traffic flow and electrical current, (a) what would correspond to the charge Q? Ohm’s Law also makes intuitive sense if you apply it to the water-and-pipe analogy. The drag imposed by the walls of the pipe is somewhat analogous to parasitic resistance. This is reminiscent of electrical diagrams with an up arrow pointing to +V, grounded pins that otherwise are not shown connecting to anything, and so on. As the current increases, approaching the limits imposed by its own internal friction and of the current that the rest of the circuit can provide, the pressure drop across the device becomes lower and lower. Electric current is equivalent to a hydraulic volume flow rate; that is, the volumetric quantity of flowing water over time. Water flowing through pipes loses pressure, just as current flowing through a resistor falls to lower voltage. Electrical current is the flow of charges making a second flow redundant. In this case, electric potential is equivalent to pressure. For this reason, waves in water travel at the speed of sound, but waves in a sea of charge will travel much faster as the forces from one electron are applied to many distant electrons and not to only the neighbors in direct contact. 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