- #1
jeff1evesque
- 312
- 0
Statement:
If a volume charge distribution existed inside a conductor at t = 0, the charges would quickly migrate to the outside surfaces due to repulsion. The rate at which the charge density would decrease is given by:
[tex]\rho_{v}(t) = \rho_{v}(t = 0)e^{-\frac{t}{t_{r}}}[/tex] where the relaxation time, [tex]t_{r}[/tex], is [tex]t_{r} = \frac{\epsilon}{\sigma}[/tex].
Question:
But to me, it seems [tex]\rho_{v}(t) = \rho_{v}(t = 0)e^{-\frac{t}{t_{r}}}[/tex] is a function that is not defined. Where is the equation that makes the charge density decrease? Both sides of the equality (above) is a function that is not defined. I feel like this equation is like saying take the equation [tex]F(y) = F(y = a)[/tex] and solve for the function F(y = a, where a could be any of the Real's), which hasn't been defined. Does anyone know how to find the (decreasing) rate of charge density from the equation given? Or even the time it takes for a particular charge density to decrease to some fixed amount say 44coulombs/m^2?
Thanks,
JL
If a volume charge distribution existed inside a conductor at t = 0, the charges would quickly migrate to the outside surfaces due to repulsion. The rate at which the charge density would decrease is given by:
[tex]\rho_{v}(t) = \rho_{v}(t = 0)e^{-\frac{t}{t_{r}}}[/tex] where the relaxation time, [tex]t_{r}[/tex], is [tex]t_{r} = \frac{\epsilon}{\sigma}[/tex].
Question:
But to me, it seems [tex]\rho_{v}(t) = \rho_{v}(t = 0)e^{-\frac{t}{t_{r}}}[/tex] is a function that is not defined. Where is the equation that makes the charge density decrease? Both sides of the equality (above) is a function that is not defined. I feel like this equation is like saying take the equation [tex]F(y) = F(y = a)[/tex] and solve for the function F(y = a, where a could be any of the Real's), which hasn't been defined. Does anyone know how to find the (decreasing) rate of charge density from the equation given? Or even the time it takes for a particular charge density to decrease to some fixed amount say 44coulombs/m^2?
Thanks,
JL
Last edited: