<Dl> <Dd> J → = E → ρ (\ displaystyle (\ vec (J)) = (\ frac (\ vec (E)) (\ rho))) or </Dd> <Dd> E → = ρ J → (\ displaystyle (\ vec (E)) = \ rho (\ vec (J))) </Dd> </Dl> <Dd> J → = E → ρ (\ displaystyle (\ vec (J)) = (\ frac (\ vec (E)) (\ rho))) or </Dd> <Dd> E → = ρ J → (\ displaystyle (\ vec (E)) = \ rho (\ vec (J))) </Dd> <P> Conduction in semiconductor devices may occur by a combination of drift and diffusion, which is proportional to diffusion constant D (\ displaystyle D) and charge density α q (\ displaystyle \ alpha _ (q)). The current density is then: </P>

Electric current in a liquid is due to the flow of