Limitations of Ohm's Law: Ohm's law states that the current flowing through a conductor is directly proportional to the voltage applied across it and invers...
Limitations of Ohm's Law:
Ohm's law states that the current flowing through a conductor is directly proportional to the voltage applied across it and inversely proportional to the resistance offered by the conductor. This law is a fundamental principle in electrical engineering and is widely applicable to various devices and circuits.
Limitations:
Temperature: The current flowing through a conductor is affected by temperature changes. When the temperature increases, the resistance of the conductor also increases. This deviation from Ohm's law is known as temperature dependence.
Conductors with Non-Zero Resistance: For conductors with a non-zero resistance, the current flowing through them is always zero, regardless of the applied voltage. This is because the voltage would have to exceed the resistance to force a current through the conductor.
Series Circuits: When multiple resistors are connected in a series configuration, the total resistance of the circuit is equal to the sum of the individual resistances. However, if the resistors have different values, the current distribution may be non-uniform, resulting in unequal voltage drops across the resistors.
Parallel Circuits: In a parallel circuit, the individual resistances are equal, and the current flows through each branch independently. This leads to a constant current flow, regardless of the applied voltage. However, if the branches have different values, the voltage across them may not be the same, resulting in non-uniform current distribution.
Superconductors: Superconductors exhibit zero resistance when subjected to a constant voltage. This means that no current flows through a superconductor regardless of the applied voltage.
Impedance: Ohm's law does not apply to impedance, which is a measure of the opposition to the flow of alternating current (AC). Impedance includes resistance and inductive reactance.
Examples:
A light bulb connected in a circuit with a fixed voltage will obey Ohm's law, with the current flowing directly proportional to the voltage applied.
A resistor connected in a series circuit with other resistors will have a fixed current, regardless of the applied voltage.
A parallel circuit with two resistors of different values will exhibit unequal voltage drops, resulting in a non-uniform current distribution