Does ohns law state that the current equals amperes divided by the restitance?

Answer 1

No, it doesn't! Ohm's Law states that 'the current passing through a conductor is proportional to the voltage applied across the ends of that conductor, providing external conditions such as temperature remain constant'. Put another way, Ohm's Law can be expressed as 'the ratio of voltage to current is constant for variations in voltage'.

In fact, very few conductors obey Ohm's Law, so that it is by no means a universal law. Those that do are called 'linear' or 'ohmic' materials, whereas those that don't are called 'non-linear' or 'non-ohmic'. Non-linear conductors include tungsten, and non-linear devices include semiconducting materials including diodes.

The ratio of voltage to current is called resistance, so you can always determine the resistance of a material, at any given voltage, by dividing that voltage by the current -whether that material obeys Ohm's Law or not.