User:AndreRD/Analogues in Physics

In Physics, there are many cases where two different phenomena that might seem unrelated share some similar underlying structure. When this happens, there is often a correspondence between the units and formulas of the two systems.

Electricity like water in a pipe
Since electrons cannot be seen and are intangible, a very popular model of explaining how electric circuit work is by the Water-in-Pipes model. This is a useful model to use because water flowing through pipes is a mechanical system that works in uch the same way as an electrical circuit, but with different units.

The main ideas are that: The power in the circuit equals the voltage times the current. The same power can be carried by a high voltage and a low current as is carried by a low voltage and a high current. The higher the current flow, however, the more energy is lost as heating of the wires. That's why high voltage and low current is used when transporting electrical energy along power lines.
 * The pipe is like the wire in the electric circuit
 * The pump is like the battery.
 * The pressure generated by the pump drives water through the pipe; that pressure is like the voltage generated by the battery which drives electrons through the circuit.
 * The seashells plug up the pipe and slow the flow of water, creating a pressure difference from one end to the other. In a similar way the resistance in the electric circuit resists the flow of electricity and creates a voltage drop from one end to the other. Energy is lost across the resistor and shows up as heat.

Correspondence Principle
---