Question on electric lines and conductor

[Shan K]

i have read that if we place an unit positive electric charge in an electric field the path in which it moves is the electric lines of force of that electric field . is it true ?

and again that the lines of force doesn't make a closed curve . is that also true ? if yes then if we can make a certain arrengement of positive or negetive charge in a manner that if we place an unit positive charge in that place it will go round and round . then the lines of force of that arrengement will be a closed curve . isin't it ?

and at last i can't understand why a conductor does not have an electric field in it ?

thanks in advance

 

[DocZaius]

i have read that if we place an unit positive electric charge in an electric field the path in which it moves is the electric lines of force of that electric field . is it true ?

No, the electric field has units of force per unit charge and so will correspond to the direction of acceleration of the positive charge.

and again that the lines of force doesn't make a closed curve . is that also true ? if yes then if we can make a certain arrengement of positive or negetive charge in a manner that if we place an unit positive charge in that place it will go round and round . then the lines of force of that arrengement will be a closed curve . isin't it ?

You need to clarify this part of your question. I think you're referring to the fact that the curl of the electric field is zero in the absence of a changing magnetic field? I'm not sure what your question about that is.

and at last i can't understand why a conductor does not have an electric field in it ?

In the static case, since charges inside a conductor are free to move, then there must not be an electric field. Otherwise they would move and it wouldn't be a static case. What this means in effect is that charges inside a conductor will spatially configure themselves such that there is no electric field inside it.

 

[Shan K]

No, the electric field has units of force per unit charge and so will correspond to the direction of acceleration of the positive charge.

so what would be the definition of electric lines of force ?

 

[Shan K]

In the static case, since charges inside a conductor are free to move, then there must not be an electric field. Otherwise they would move and it wouldn't be a static case. What this means in effect is that charges inside a conductor will spatially configure themselves such that there is no electric field inside it.[/QUOTE]

is there any dynamical case ?