184_notes:resistivity

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
184_notes:resistivity [2021/02/24 17:45] bartonmo184_notes:resistivity [2021/02/27 04:07] (current) – [Making sense of $R$] bartonmo
Line 56: Line 56:
 Why does the bottom fraction make sense? A longer, thinner wire should be more resistive, so the geometric properties make sense (directly proportionally to $L$ and inversely proportional to $A$). A wire with higher conductivity should be less resistive, which also make sense (inversely proprtional to $\sigma$). Why does the bottom fraction make sense? A longer, thinner wire should be more resistive, so the geometric properties make sense (directly proportionally to $L$ and inversely proportional to $A$). A wire with higher conductivity should be less resistive, which also make sense (inversely proprtional to $\sigma$).
  
-Resistance has units of volts per amp, which is also called an ohm. An ohm is represented by a capital omega ($\Omega$). Sometimes you may see resistance rewritten in terms of **resistivity**($\rho$), which is simply the inverse of conductivity $\rho=1/\sigma$. So using resistivity, $R=\frac{\rho L}{A}$ - either version of resistance is fine. +**Resistance has units of volts per amp, which is also called an ohm.** An ohm is represented by a capital omega ($\Omega$). Sometimes you may see resistance rewritten in terms of **resistivity**($\rho$), which is simply the inverse of conductivity $\rho=1/\sigma$. So using resistivity, $R=\frac{\rho L}{A}$ - either version of resistance is fine. 
  
 ==== Ohm's Model ==== ==== Ohm's Model ====
  • 184_notes/resistivity.txt
  • Last modified: 2021/02/27 04:07
  • by bartonmo