4 ms·

The way the analogy was explained to me when i was a student is that the conductor is a hose filled with water, when you open the valve the water comes out inst

The way the analogy was explained to me when i was a student is that the conductor is a hose filled with water, when you open the valve the water comes out instantly at the other end because the "charge" is moving. It was never confusing to me.

jcims 8y ago
I think anyone that has waited for hot water to get to the tap understands this. Pressure (voltage) transmits at the speed of sound (light). The speed of the particles through the medium, on the other hand, depends on many factors.
hexane360 8y ago
This is the correct way. In the water analogy, the circuit is a closed system and components are completely filled with water at all times. For example, the capacitor is a filled sphere with a rubber divider. The total amount of charge/water is constant, but you can change how it is divided between the two plates by an applied voltage/pressure.
fjsolwmv 8y ago
The analogy is valid and hydraulic circuits work. If people transfer their incorrect understanding of water to incorrect knowledge of electricity, that doesn't make the analogy bad.
mbell 8y ago
I think the analogy can work, but needs to be carefully applied. This wasn't an analogy taught in my EE program, but one that is common in TV programming and provided by high school science teachers whom may not themselves understand the nuance so many came into the program with this understanding in place. Ultimately though, this concept was the breaking point for my EE class; It's when half the class dropped out to other majors. Not that I blame the analogy entirely for this, I think in general this is the point at which a lot of people lose connection with deeper sciences. It's the point where analogies to the physical world (matter) break down because we're now fundamentally talking about energy, which doesn't obey the rules all humans are accustom to. The world where we can't see it or relate it to our daily experiences but only talk about it through mathematics.

jcims 8y ago

I think anyone that has waited for hot water to get to the tap understands this. Pressure (voltage) transmits at the speed of sound (light). The speed of the particles through the medium, on the other hand, depends on many factors.

hexane360 8y ago

This is the correct way. In the water analogy, the circuit is a closed system and components are completely filled with water at all times. For example, the capacitor is a filled sphere with a rubber divider. The total amount of charge/water is constant, but you can change how it is divided between the two plates by an applied voltage/pressure.

fjsolwmv 8y ago

The analogy is valid and hydraulic circuits work. If people transfer their incorrect understanding of water to incorrect knowledge of electricity, that doesn't make the analogy bad.

mbell 8y ago

I think the analogy can work, but needs to be carefully applied. This wasn't an analogy taught in my EE program, but one that is common in TV programming and provided by high school science teachers whom may not themselves understand the nuance so many came into the program with this understanding in place. Ultimately though, this concept was the breaking point for my EE class; It's when half the class dropped out to other majors. Not that I blame the analogy entirely for this, I think in general this is the point at which a lot of people lose connection with deeper sciences. It's the point where analogies to the physical world (matter) break down because we're now fundamentally talking about energy, which doesn't obey the rules all humans are accustom to. The world where we can't see it or relate it to our daily experiences but only talk about it through mathematics.