The limitations of Ohm’s law are explained as follows:
1) This law cannot be applied to unilateral networks.
A unilateral network has unilateral elements like diode, transistors, etc., which do not have same voltage current relation for both directions of current.
2) Ohm’s law is also not applicable for non – linear elements.
Non – linear elements are those which do not give current through it, is not exactly proportional to the voltage applied, that means the resistance value of those elements changes for different values of voltage and current. Examples of non – linear elements are thyristor, electric arc, etc.
3) V depends on I non-linearly.
4) The relationship between V and I depends on the sign of V for the same absolute value of V.
5) The relation between V and I is non-unique, that is, for the same current I, there is more than one value of voltage V.
6) Ohm’s law is not followed by semiconductors. The V-I graph has a steep rising at a particular voltage, which indicates that the material begins to conduct properly only after a certain voltage.
Md Rafay Nadvi
The limitations of Ohm’s law are explained as follows:
1) This law cannot be applied to unilateral networks.
A unilateral network has unilateral elements like diode, transistors, etc., which do not have same voltage current relation for both directions of current.
2) Ohm’s law is also not applicable for non – linear elements.
Non – linear elements are those which do not give current through it, is not exactly proportional to the voltage applied, that means the resistance value of those elements changes for different values of voltage and current. Examples of non – linear elements are thyristor, electric arc, etc.
3) V depends on I non-linearly.
4) The relationship between V and I depends on the sign of V for the same absolute value of V.
5) The relation between V and I is non-unique, that is, for the same current I, there is more than one value of voltage V.
6) Ohm’s law is not followed by semiconductors. The V-I graph has a steep rising at a particular voltage, which indicates that the material begins to conduct properly only after a certain voltage.