After seeing contradictory posts on many forums , and getting differing opinions from my teachers , i'm completely lost with the ohms law.... I have a number of questions. Can someone please answer them for me? 1) Do semiconductors obey Ohms law? and why do they obey/not obey? if they obey , then why is the drop across a ideal diode constant even when the current in it changes? 2) I heard someone say in another thread "semiconductors obey ohms law , but semiconductor junctions dont". why is it so? 3) A thread in another forum said that liquids dont obey ohms law as ions are the current carriers... true or false? 4) Is ohm's law a special case of V=IR or is V=IR a special case of ohms law? 5) Is Ohms law a law at all? 6) Is there any theory in physics which explains why ohms law works the way it does?