Ohm's Law relates voltage, current, and resistance in a circuit. It states that the voltage (V) across a component in an electrical circuit is directly proportional to the current (I) flowing through it and the resistance (R) of that component. The relationship is described by the formula:
V = I * R
Where:
V = Voltage across the component (in volts)
I = Current flowing through the component (in amperes)
R = Resistance of the component (in ohms)
However, when dealing with reactive components like inductors and capacitors, we need to consider reactance (X) instead of resistance, as reactance is specific to these elements.
The reactance (X) of an inductor or capacitor depends on the frequency (f) of the AC (alternating current) signal passing through it. For an inductor, reactance is given by:
X_L = 2π * f * L
Where:
X_L = Inductive reactance (in ohms)
f = Frequency of the AC signal (in hertz)
L = Inductance of the inductor (in henrys)
For a capacitor, reactance is given by:
X_C = 1 / (2π * f * C)
Where:
X_C = Capacitive reactance (in ohms)
C = Capacitance of the capacitor (in farads)
Now, Ohm's Law can be extended to include reactance. The voltage across a reactive component (inductor or capacitor) can be calculated using the following formula:
V = I * X
Where:
V = Voltage across the reactive component (in volts)
I = Current flowing through the reactive component (in amperes)
X = Reactance of the reactive component (in ohms)
So, in summary, Ohm's Law relates voltage, current, and resistance in a circuit, but when dealing with reactive components, the concept of reactance is introduced, and Ohm's Law can be extended to include reactance in the calculation of voltage across these elements.