- Inductance is the relationship between the current and the magnetic field generated in a coil. Each is proportional to the delta of the other.
[latex]
{\large
\frac{L = ( d^2 n^2)}{l + 0.45d}
}
[/latex][latex]d2[/latex] is diameter of coil in meters
[latex]n[/latex] is number of coil turns
[latex]I[/latex] is length of coil in meters
- Resistance (R) is not affected by AC voltage or current frequency and remains the same for AC/DC
[latex]
{\normalsize
R =
\frac{V}{I}
}
[/latex]
-
Reactance (X) or Back EMF is the opposition to current flow in proportion to the current frequency
- Inductive reactance (XL) rises with an increase in frequency:
[latex]2πƒL[/latex]
- Capacitive reactance (XC) rises with a decrease in frequency:
[latex]
{\large
\frac{1}{2πƒC}
}
[/latex]
- Inductive reactance (XL) rises with an increase in frequency:
-
Impedance describes the combined effect of resistance (R), inductive reactance (XL) and capacitive reactance (XC) in an AC circuit
For DC circuit:
[latex]Z = \sqrt{( R^2 + (XC^2) )}[/latex]
For AC circuit:
[latex]Z = \sqrt{( R^2 + (XL – XC)^2 )}[/latex]