Depending on the material of the resistance element, resistors are classified into linear resistors and non linear resistors. Majority of the resistors used in electronic circuits are linear resistors. Those resistors which follow ohm’s law and have linear voltage-current characteristics are called linear resistors. Those resistors which do not obey ohm’s law are called non-linear resistors. Those resistors which do not obey ohm’s law are called non-linear resistors. Those resistors which do not obey ohm’s law are called non-linear resistors. Various types of resistors are mentioned.