Assumptions
edit
- Electrons act as classical charged particles
- Collisions are random and elastic
- Probability of scattering during a short period of time dt:
- After each scattering event, the mean momentum is zero
- Between scattering events, electrons experience the Lorentz force:
Ignored details:
edit
- Electrons may collide or interact with nuclei
- Obstacles are just lumped into scattering term
- Charge is ignored during collisions
- Electrons are quantum particles, so elastic collisions are inaccurate!
Mathematical Description
edit
Consider the change in momentum over dt.
What can happen during dt?
- Scatter: , avg. momentum = 0
- Not-scatter: , Lorentz force
Predicting Known Relations
edit
For the following scenarios, assume a constant E-field.
Ohm's Law
edit
Limitations
edit