# Current Discrepancy: Why Positive Charge?

• Opario
In summary, the direction of current in a wire is often referred to as the "movement" of positive charge, which may be more advantageous to think about than the negative charge on electrons. This assumption was made before electrons were discovered and there was a 50% chance of being right. Additionally, the north pole of a compass needle is termed the "North Seeking" pole, but this can change over time as the magnetic poles flip with regularity. When studying solid state physics, it is common to think about electron movement rather than positive charge. However, when working with circuits and meter readings, it may be easier to switch back to the positive charge perspective. Ultimately, it depends on the context and what is being studied.

#### Opario

Why would it be an advantage to say that the direction of current in a wire is the "movement" of positive charge, when in fact it is the negative charge on electrons which is moving. And who decided to make that the universal rule, anyway?

And another thing: Isn't the north pole of the Earth really the south pole?

Opario said:
Why would it be an advantage to say that the direction of current in a wire is the "movement" of positive charge, when in fact it is the negative charge on electrons which is moving. And who decided to make that the universal rule, anyway?

Back before electrons were discovered, they had to make an assumption... 50% chance of being right...

Opario said:
And another thing: Isn't the north pole of the Earth really the south pole?

As I recall, the "N" end of a compass needle is termed the "North Seeking" pole.

Since the magnetic poles flip with monotonous regularity, if you hang around long enough the "N" of the compass needle will become the "South Seeking" pole...

Opario said:
Why would it be an advantage to say that the direction of current in a wire is the "movement" of positive charge, when in fact it is the negative charge on electrons which is moving.
I just find it easier to think about the direction positive charges would move in a circuit, rather than thinking about negative charge motion and continually reminding myself that the voltmeter or ammeter readings need a sign change.

Redbelly98 said:
I just find it easier to think about the direction positive charges would move in a circuit, rather than thinking about negative charge motion and continually reminding myself that the voltmeter or ammeter readings need a sign change.

After you start taking your first solid state physics class, you will probably think more in terms of electron movement. It's physically what's going on, after all, and it turns out not to be very hard to make the mental flip to "positive" current direction.

berkeman said:
After you start taking your first solid state physics class, you will probably think more in terms of electron movement. It's physically what's going on, after all, and it turns out not to be very hard to make the mental flip to "positive" current direction.

In that situation, yes you're absolutely right. It all depends on what you are working on. My first (and only) solid state physics class was about 25 years ago. These days I often work with circuits and meter readings.

When I look at what's going on in diodes and transistors I switch back to the electron point of view, it's easier in terms of understanding the physics as you point out.

Regards,

Mark