Saved Bookmarks
| 1. |
What r the limitations of Ohm\'s law ? |
|
Answer» Ohm’s Law: The current flowing through a conductor is directly proportional to the voltage applied to across the ends of the conductor.So, the V-I graph for a conductor following the Ohm’s law is a straight line with a positive slope. Limitations of this law:1. Now, this law is valid for conductors only and that too at a constant temperature. The resistance of a conductor increases with temperature. Hence, for changing temperature the V-I graph for a conductor will be non-linear (not a straight line). 2. In case of insulators ohm’s law is not followed at all, insulators do not conduct at all. But, when a very high voltage is applied across an insulator dielectric break down occurs and all of a sudden current begins to flow. 3. 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. Ohm\'s law is not applicable for metal conductors and gaseous conductors Ohma law holds good only when the physical conditions of the conductor(resistor,load) remains the same |
|