Ohm's Law
Ohm's law is an empirical law relating the voltage V across an element to the current I through it:
(V is directly proportional to I). This law is not always true: For example, it is false for diodes, batteries, etc. However, it is true to a very good approximation for wires and resistors (assuming that other conditions, including temperature, are held fixed). Materials or objects where Ohm's law is true are called "ohmic".
For ohmic materials, the resistance R and conductance G are defined by:
Therefore, resistance and conductance are inverses:
Read more about this topic: Electrical Resistance And Conductance
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