If we know that in reality electrons flow from negative to positive, then why is the negative terminal of a battery usually still connected as the ground, and things such as switches usually connect in series to the positive side?
In: Physics
Mostly because the convention of electron flow direction is completely inconsequential for day-to-day activities, we just find that cars rust a little bit less when grounded on the negative terminal than when grounded on the positive terminal
You’re mistaking “ground” with “common”. Most battery powered and DC devices aren’t grounded. Instead, their chassis or major metallic components are connected to one leg of the battery, typically the -. This actually aligns with the correct model of electricity flow.
You can call anything in a circuit “ground”. “Ground” is just a reference point.
Ground can be anywhere in the circuit, but it is usually near the power supply, because current going into or coming out of ground needs to go somewhere.
None of this has anything to do with the direction that electrons move. Grounding, battery directions, and switch connections are decided by three things:
What is convenient, what is necessary, and if it doesn’t matter then a choice is arbitrary. “The real direction of electrical flow” is none of these things.
We don’t, not necessarily. The terminal we choose as ground is pretty arbitrary, and positive grounded vehicles have existed for a while. We tend not to do it nowadays because negative grounding reduces galvanic corrosion of the frame of vehicles.
The knowlage of the chage of the particle that moves is later then convention of what is positive and negative.
If you would change is you would either need new symbols and names or have a period where it is had to know what standard is used. It is simple to just keep the convention.
In practice it very seldom matter if you look at it as electricity that flow from + to – instead of elections that flow from – to +. In some application it do matter like in vacuum tubes where the negative catode is heated to get it to emmit free elections easier.
If you look at semiconductors the simples way to think of it is there are both negative and possitve changes that move around. A positive charge is called a hole, short for electron holes, that is where there is a missing electron. It do not matter that holes are not particle by themself it work the same if you consider a missing electron. But it is easier to understand if you have tow particles.
Ground is just what we define as a voltage of 0. For AC system, like most are when there is a physical connection to the physicals ground you have both positive and negative voltages. If you would flip the definition you would still have positive and negative voltages relative to the new ground. The only diffrence is when in time the voltage is positive or negative.
So the practical advantage to changing it is very low compared the problem you will have after the change in knowing what system is used.
Because the positive terminal is charged by removing electrons from that end of the battery, which takes work. When you connect it to the negative end, you are allowing stray electrons to push towards the electron “holes” on the positive end.
In general, there aren’t many electrons that actually move from one end to the other. It is just that the lack of electrons on one end attracts all the electrons crowded in the metal conductors like they were cars on a highway at rush hour.
Negative is usually connected as ground because a large metal object usually has an excess of electrons which – if pulled away – won’t cause an imbalance of voltage in it. It can be called a current source (or sink, to ground excess current in the circuit).
Electrons are negatively charged. We’re concerned with positive flow.
If you say “wait that’s arbitrary”
Yes.
We can arbitrarily flip the sign to electrons to positive if you want, just convince the world to do it because some people like you care about it.
Fun fact, Russian jets used to have it reversed. They had positive going to ground, negative to power. Almost made a big mistake first time I went to put a battery back in.
Because iirc the electric field is made from positive to negative which then causes electrons to flow negative to positive.
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