Current and Electric Field Direction for Electrons Moving Right

[jauser]

Homework Statement

Electrons move to the right in a certain wire. This indicates that:
a) the current and electric field both point right
b) the current and electric field both point left
c) the current points right and the electric field points left
d) the current points left and the electric field points right
e) the current points left but the direction of the electric field is unknown

Homework Equations

don't know any since this is not a computational question?

The Attempt at a Solution

First the current direction would be opposite of the electrons' direction. So then I was using the RHR which has your thumb in the direction of the current. And with that the electric field would point INTO the page.
But the right answer is b), can someone help?

Thank you!

 

[Stonebridge]

The RHR is for finding the direction of magnetic fields.
If electrons move to the right then conventional current, which is a flow of positive charge, moves to the left.
The direction of the electric field is the direction of the force on a positive charge.
That is, in this case, the direction of the force that moves the (positive) charges in this wire.
Which way is that?

 

[jauser]

That would be the left.
So let me hammer this in my head. Since an electric field came about by the creation of electric charges it will go with the direction of the charge?

Is it (the electric field) ever perpendicular to the charge(s)?

 

[Stonebridge]

Yes, the electric field is to the left, in the same direction as the positive charges move.

You can apply an external electric field perpendicular to a beam of electrons, for example, if you want to deflect them.
This is exactly what is done in an oscilloscope to deflect the beam of electrons (cathode rays) up or down, and left to right.

 

[jauser]

OK it makes sense now. Thank you very much.

Props!