Asked in Electrical Engineering
How do you know that the conductor used obeyed ohm's law?
May 14, 2012 7:12AM
A conductor obeys Ohm's Law if the ratio of voltage to current remains constant over a wide range of voltage variations -and, then, only over that particular range of voltages. Put another way, a graph plotted of current against voltage must be a straight line. If the ratio of voltage to current varies, or if the resulting graph is anything other than a straight line, then the conductor does not obey Ohm's Law.
Ohm's Law is by no means an universal law, and only a limited number of materials obey Ohm's Law. Those that do are called 'ohmic' or 'linear' materials; those that don't are called 'non-ohmic' or 'non-linear'.