AC Voltage Applied To Inductor
In case of a DC circuit, an inductor acts as a closed connection offering no resistance to current. But in AC currents, an inductor’s voltage drop equation is:
A simple inductor connected to an AC power source:
Voltage across the source be , Vm is Max voltage
As per Kirchhoff’s loop rule, voltage equation is:
Where L is the inductance of the inductor and is self-induced Faraday emf in the inductor. Negative sign follows from Lenz’s law.
Equation now becomes :
To obtain the current, we integrate di/dt with respect to time:and get
The source has an emf which oscillates symmetrically about zero, the current it sustains also oscillates symmetrically about zero, so that no constant or time-independent component of the current exists. Therefore, the integration constant is zero.
Thus equation becomes , Where im is and Xl = ω L
amplitude of the current is,. Dimension of inductive reactance is the same as that of resistance and its SI unit is ohm