When can you not use Ohm's law?
2 Answers
Ohm's law, which states \( V = IR \), applies to ohmic materials where the resistance remains constant regardless of voltage and current. You can't use Ohm's law when dealing with non-ohmic materials, like diodes or transistors, where resistance changes with voltage or current. It also doesn't apply in situations involving superconductors at temperatures below their critical temperature or in circuits with highly variable or reactive components like inductors and capacitors. In such cases, you need to use more complex methods to analyze the behavior of the circuit.
Ohm's Law (V = IR) is not applicable in certain scenarios. It breaks down in non-ohmic materials where resistance changes with voltage or current, such as in semiconductors and diodes. It also fails in circuits with components that exhibit significant reactance, like capacitors and inductors, especially at varying frequencies. Additionally, it doesn’t apply in situations involving superconductors, where resistance drops to zero under certain conditions. Are there specific types of circuits or components you're curious about?