The inductor shown in Figure 16–8 has an inductance of 0.8 H and is connected to a 120-V, 60-Hz line.How much current will flow in this circuit if the wire resistance of the inductor is negligible?
The first step is to determine the amount of inductive reactance of the inductor:
X_{L} = 2πfL
X_{L} = 2 × 3.1416 × 60 Hz × 0.8
X_{L} = 301.594 Ω
Because inductive reactance is the current-limiting property of this circuit, it can be substituted for the value of R in an Ohm’s law formula:
I = {\frac{\operatorname{E}}{X_{L}}}
I = {\frac{120\,\mathrm{V}}{301.594\,\Omega}}
I = 0.398 A
If the amount of inductive reactance is known, the inductance of the coil can be determined using the formula
L = {\frac{X_{L}}{2\pi f }}