# I The source of the electric field of a battery?

#### rude man

Homework Helper
Gold Member
Obviously a potential difference can be defined because that is how we normally define a battery.
A resistor also has potential difference. See, a resistor differs from a battery in that current flows from - to + but for the resistor it's + to -. EMF makes the difference.
A battery is defined by its emf, not its potential difference. A resistor has no emf across it.
........gravity...................
So show me a massless charged particle
How many orders of magnitude is gravitational force typically less than electric? You'd have a hell of a time trying to move an electron with gravity ...

#### hutchphd

A resistor also has potential difference. See, a resistor differs from a battery in that current flows from - to + but for the resistor it's + to -. EMF makes the difference.
A battery is defined by its emf, not its potential difference. A resistor has no emf across it.How many orders of magnitude is gravitational force typically less than electric? You'd have a hell of a time trying to move an electron with gravity ...
Ever do the Millikan Oil drop experiment??

#### rude man

Homework Helper
Gold Member
Ever do the Millikan Oil drop experiment??
Er, let me explain. The effect of gravity is on the oil, not the electron. The effect on the electron is due to an electric field.

#### hutchphd

No, let me explain (again)
It is certainly true that electromagnetic forces control every aspect of a common battery and that the work done on the electrons to provide them emf is all electromagnetic. But to talk about "an electric field" implies a well-described and static structure that does not comport with reality. The process is complicated and dynamic and not characterized by "an electric field". It involves many different electric fields over an electron's trajectory and so the statement should be discouraged.. What is well defined is the path integral for each electron which we call the potential.
Of course it is electrical. But you offered the Nobel..............how could I refuse?

#### sophiecentaur

Gold Member
I think the 'source' can be looked upon as what causes any chemical reaction, only in this case the charge imbalance is carried around by a wire. The electrolyte helps the process along by allowing ions to form at the electrode surfaces.

#### gleem

You'd have a hell of a time trying to move an electron with gravity ...
Although the gravitational force is infinitesimal compared to electrical forces none the less an electron is easily moved by gravity as the gravitational force on any mass is independent of the mass meaning in a vacuum all masses are accelerated at 9.8 m/sec2. The force of gravity on an electron is equal to the force produced by a coulomb field of 5.6 x10-11 V/m, the field produced by another electron 5.1 m away. So the electric fields produced at the atomic level of about 1 nm are huge.

"The source of the electric field of a battery?"

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving