Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: labview1958 on 16/01/2009 08:45:46

Title: electric field lines
Post by: labview1958 on 16/01/2009 08:45:46

Why do electric field lines are drawn away from a positive charge and towards for a negative charge. Is it a conventional method or there is some physics behind it?

Title: electric field lines
Post by: Chemistry4me on 16/01/2009 08:53:34

Conventional current? Back then they thought that electrons flowed from the positive terminal to the negative terminal.

Title: electric field lines
Post by: Soul Surfer on 16/01/2009 10:12:52

The start of the study of electricity came from static electricity generated by rubbing materials with cloths notably glass rods with silk to charge a rod one way and ebonite(plastic) rods with fur  to generate the opposite charge on the rod.

At the time they created the models and convention the choice of "positive" and "negative" (or red and green  they could have used anything)  was purely arbitrary as they had no idea of the nature of the charge carriers.

Title: electric field lines
Post by: lyner on 16/01/2009 10:30:39

Quote from: Chemistry4me on 16/01/2009 08:53:34

Conventional current? Back then they thought that electrons flowed from the positive terminal to the negative terminal.

The original model of electricity didn't involve electrons. It didn't consider charge to be quantised at all but had to choose a 'sign' and happened to make an unfortunate (for students) choice.

Title: electric field lines
Post by: Chemistry4me on 16/01/2009 10:36:37

Quote from: sophiecentaur on 16/01/2009 10:30:39

The original model of electricity didn't involve electrons. It didn't consider charge to be quantised at all but had to choose a 'sign' and happened to make an unfortunate (for students) choice.

Opps... [:I] [:I] Okay, thank you [:)].

Title: electric field lines
Post by: labview1958 on 16/01/2009 11:37:39

I am talking about electrostatic positive and negative charges. Why are field lines drawn away from a positive charge.

 

Title: electric field lines
Post by: lightarrow on 16/01/2009 11:49:00

Quote from: labview1958 on 16/01/2009 11:37:39

I am talking about electrostatic positive and negative charges. Why are field lines drawn away from a positive charge. 

The electric field is a vector; its direction is the direction of a force applied on a positive charge, by definition. Since two positive charges repel each other and a negative and a positive attracts each other, the electric field direction must go away of a positive charge and towards a negative one.

Title: electric field lines
Post by: LeeE on 16/01/2009 17:13:09

Isn't this just because we live in a matter universe and not an antimatter one?  That is, we deal with a flow of electrons, and not positrons?

Title: electric field lines
Post by: lightarrow on 16/01/2009 18:00:05

Quote from: LeeE on 16/01/2009 17:13:09

Isn't this just because we live in a matter universe and not an antimatter one?  That is, we deal with a flow of electrons, and not positrons?

What would change in that case?

Title: electric field lines
Post by: lyner on 16/01/2009 21:34:08

I think you need to check up on what constitutes matter and antimatter, particles and antiparticles.