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Ohms law implies specific condition for the charge density |
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| Aug10-12, 11:05 AM | #1 |
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Ohms law implies specific condition for the charge density
We have all seen Ohms law, J=σE. This approximations makes sense in simple electric fields in which the charges are accelerated in parallel.
However as I will demonstrate, this implies a few conditions on the charge density (ρ) associated with the current density (J). Now, from the continuity equation, ∂ρ/∂t=-DivJ =-σDivE (using the approximation) =-σ(ρ/ε) (From maxwells equations) This is just a simple partial differential equation, solving... ρ=A(x,y,z)exp(-σt/ε)+B(x,y,z) This is a partial differential equation, so we have to allow the coefficients and constants as functions of position. This implies that at time 0 (when the electric field is set up), the charge density is A+b, after some time the charge density reduces to B(x,y,z). Has this been observed in ohmic resistors? I find this result quite strange, is this a physical result? |
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