Electrical resistivity and conductivity results in the important concept of "quasineutrality", which says the density of negative charges is approximately equal to the density of positive charges over large volumes of the plasma ("n" = <Z>"n"), but on the scale of the Debye length there can be charge imbalance. In the special case that "double layers" are formed, the charge separation can extend some tens of Debye lengths. The magnitude of the potentials and electric fields must be determined by means other than simply finding the net charge density. A common example is to assume that the electrons satisfy the Boltzmann relation: Differentiating this
Negative and positive rights Negative and positive rights Negative and positive rights are rights that oblige either action ("positive rights") or inaction ("negative rights"). These obligations may be of either a legal or moral character. The notion of positive and negative rights may also be applied to liberty rights. To take an example involving two parties in a court of law: Adrian has a "negative right to x" against Clay if and only if Clay is "prohibited" from acting upon Adrian in some way regarding "x". In contrast, Adrian has a "positive right to x" against Clay if and only if Clay is obliged