2
$\begingroup$

I would like to ask something that bothers me. A lot of us know of the electron flow notion, which it is the technical representation of how the electron charge really flows, starting from the negative side and flowing to the positive side, as opposed to the conventional flow notion by Benjamin Franklin with flow from positive to negative.

There are two things then I like to know regarding this:

  • Is the ground (GND) the real electron reservoir? In a lightning strike, is the surface of the Earth then negative (-) and the cloud positive (+)?

  • Do electronic devices for measurement and testing (multi-meters) use the electron flow notion?

Improve this question
$\endgroup$
1
  • $\begingroup$ Hi Anon, and welcome to Physics.SE! I've tried to clean up the English in your post. I removed the last sentence about a circuit, since I found it impossible to parse. Please make sure your question still reflects what you want to ask - if you're not happy with it you can edit it, or roll back to the previous version (from the 'edit' interface). $\endgroup$
    – Kyle Oman
    Commented Aug 13, 2015 at 22:52

1 Answer 1

Reset to default
0
$\begingroup$

First of all, there is no need to worry over this. The reason we can get away with using conventional flow even though electron flow is what is really happening is that the two are indistinguishable except for in some experiments that are really hard to do.

On to your questions. The GND is not an "electron reservoir". First of all, in most circuits there is not (or should not) be any charge flow in or out of GND. When there is flow in or out of GND it could be in either direction (GND could be a source or sink of electrons). In a typical circuit electrons flow out of a negative terminal (say of a battery) and into a positive terminal.

I'm not an expert on lightning, but my understanding is that the electron current is from the cloud to the ground. In other words conventional current is from the ground to the cloud. The cloud is negative, whether you are talking about conventional current or electron current.

Multimeters use conventional current. This only affects the sign of the measurements they provide.

Improve this answer
$\endgroup$
3
  • $\begingroup$ "the two are indistinguishable except for in some experiments that are really hard to do." Er ... the Hall effect will tell you which actually obtains, and that's not particularly hard to do. $\endgroup$
    – dmckee --- ex-moderator kitten
    Commented Aug 14, 2015 at 5:16
  • $\begingroup$ Isn't the sign of the Hall voltage independent of whether the charge carriers are electrons or holes in much the same way that when we calculate a motional emf it doesn't matter whether we think about conventional current or electron current? The hard experiment I'm talking about is the Stewart-Tolman experiment. $\endgroup$
    – gleedadswell
    Commented Aug 18, 2015 at 3:47
  • $\begingroup$ The direction of force on the charge carriers is the same, making the sign of the Hall voltage diagnostic. $\endgroup$
    – dmckee --- ex-moderator kitten
    Commented Aug 18, 2015 at 4:34

Not the answer you're looking for? Browse other questions tagged or ask your own question.