Question
State the limitations of ohm's law.

Answer

(1) In some devices V and I are not proportional to each other.

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(2) The relation between V and I depends on the sign of V. In other words, if I is the current for a certain value of V , then reversing the direction of V keeping its magnitude fixed, does not produce a current of the same magnitude as I in the opposite direction. This happens in case of diode.

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(3) The relation between V and I is not unique means there are more than one value of V for the same current I. for example, GaAs (Gallium Arsenide).

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