# Homework Help: Permittivity (background reading from Wikipedia)

1. Jul 16, 2009

### jeff1evesque

I read the following from Wikipedia,

Question
How does a dielectric's dipole becoming polarized

2. Jul 16, 2009

### Staff: Mentor

Look at the electric field between the separated parts of the dipole... doesn't it go the opposite way of the overall field?

3. Jul 16, 2009

### jeff1evesque

I am not sure, could you elaborate more. All I know as of now is that dipoles are not necessarily aligned, and when the electric field is applied (I think?), then the dipoles align.

Thanks,

JL

4. Jul 16, 2009

### negitron

Right. In what direction do they align, in terms of polarity, with respect to the applied external E field?

5. Jul 16, 2009

### jeff1evesque

The negative end of the dipole matches with (in the direction) of positive charges (capacitor or other dipoles)? And between a capacitor, could there be many dipoles spanning the distance between the two plates ?

6. Jul 16, 2009

### negitron

Okay, and when you have one electric field oriented in one direction and another in the opposite one the net field is...?

7. Jul 16, 2009

### jeff1evesque

Got it, zero (if they are equal-which they are in this situation).

Thanks,

Jeff