- #1
Noesis
- 101
- 0
1. The problem statement
The explanation of resistance in my textbook and given by my teacher (when I actually took the class) doesn't make much sense upon analysis to me.
From the model that I was taught, resistance is explained as such:
The charge carriers are flowing in current, and will periodically run into 'atoms.' This causes them to pause for a moment and slow down due to the collision, and then pick up speed again due to the electric field pressing them on.
The atoms then vibrate from the collision, and thus the kinetic energy imparted into the atoms is released as thermal energy. Which is why resistors heat up and whatnot.
Analysis and problem with model
Now this doesn't make much sense when I think about what atoms are.
In a metallic conductor the electrons are what are flowing in a 'sea' of them. So the electrons are what would bump into atoms.
Atoms are mostly empty space. There are electrons kind of orbitting about and at the very center the nucleus composed of protons and neutrons. So for an electron to hit an atom, what we are saying is that the electrons are hitting either other electrons or the nucleus.
It is impossible for them to hit other electrons (or so I think) because they would repel each other with immense force.
If an electron manages to hit the nucleus, the attractive force between the two should be so strong that it should no longer continue to move. Seeing as how the attractive force varies inversely proportional to distance squared, when the electron comes within such close range of the protons, and actually strikes them, the attractive force should be huge and should easily overcome whatever is producing the field/voltage that made the electron start to move in the first place.
So what gives?
The explanation of resistance in my textbook and given by my teacher (when I actually took the class) doesn't make much sense upon analysis to me.
From the model that I was taught, resistance is explained as such:
The charge carriers are flowing in current, and will periodically run into 'atoms.' This causes them to pause for a moment and slow down due to the collision, and then pick up speed again due to the electric field pressing them on.
The atoms then vibrate from the collision, and thus the kinetic energy imparted into the atoms is released as thermal energy. Which is why resistors heat up and whatnot.
Analysis and problem with model
Now this doesn't make much sense when I think about what atoms are.
In a metallic conductor the electrons are what are flowing in a 'sea' of them. So the electrons are what would bump into atoms.
Atoms are mostly empty space. There are electrons kind of orbitting about and at the very center the nucleus composed of protons and neutrons. So for an electron to hit an atom, what we are saying is that the electrons are hitting either other electrons or the nucleus.
It is impossible for them to hit other electrons (or so I think) because they would repel each other with immense force.
If an electron manages to hit the nucleus, the attractive force between the two should be so strong that it should no longer continue to move. Seeing as how the attractive force varies inversely proportional to distance squared, when the electron comes within such close range of the protons, and actually strikes them, the attractive force should be huge and should easily overcome whatever is producing the field/voltage that made the electron start to move in the first place.
So what gives?