- #1
Jonsson
- 79
- 0
Hello there,
I want to derive ##U(\theta) ## for electric dipole placed in uniforum electric field $\vec{E} = E\vec{e}_x$ where E is constant. I define the dipole moment as $p = qd$, where $d$ is the distance from the two
I write $\mathm{d}W = p\,E\sin\theta \mathrm{d}\theta = \tau\mathrm{d}\theta$, but how do I determine what the sign should be? Should it be $\tau\mathrm{d}\theta$ or $-\tau\mathrm{d}\theta$?
I don't understand how to work it out. What determines what the sign should be?
Thank you for your time.
Kind regards,
Marius
I want to derive ##U(\theta) ## for electric dipole placed in uniforum electric field $\vec{E} = E\vec{e}_x$ where E is constant. I define the dipole moment as $p = qd$, where $d$ is the distance from the two
I write $\mathm{d}W = p\,E\sin\theta \mathrm{d}\theta = \tau\mathrm{d}\theta$, but how do I determine what the sign should be? Should it be $\tau\mathrm{d}\theta$ or $-\tau\mathrm{d}\theta$?
I don't understand how to work it out. What determines what the sign should be?
Thank you for your time.
Kind regards,
Marius