- #1
JulienB
- 408
- 12
Homework Statement
Hi everybody! I'm unsure how to tackle the following problem, hopefully some of you can give me some hints on how to do so. :)
How big is the force acting on an anode by an electron current of strength ##I=0.3##A if the electrons are accelerated with a voltage ##U=300##V?
Homework Equations
##\vec{F} = q \cdot \vec{E}##
##I = dQ/dt##
The Attempt at a Solution
I think I'm missing something here. I've drawn a picture of how I understand the problem, please let me know if something is wrong with my interpretation.
So the force should be ##F = q \cdot E## with ##q = -e## being the charge of an electron. My problem is the electric field, I cannot seem to find a way to calculate it! Other things I've tried/noticed:
##I = q/t## since the current is constant, so I could solve for ##t## for an elementary charge. Does that make sense? I think I'd rather have ##q = I \cdot t##, and then ##F = I \cdot t \cdot E##. When I try to find ##E## using Gauss law, I get ##E = \frac{q}{\epsilon_0 A}## but that's a dead end since I don't have the area.
Surely I am missing an equation relating ##U## and ##E##. Does anybody have a suggestion?Thanks a lot in advance for your answers.Julien.