# Fundamental Physics/Electricity/Inductor

## Inductor

Inductor is a electric component that can store magnetic field energy

## Construction

Capacitor is made from a straight line conductor of several circular turns

$L=N\mu {\frac {l}{A}}$ ## Inductor in DC Circuit

### Inductance

Inductance has a symbol L measured in Henry unit H

$L={\frac {B}{I}}$ ### Magnetic Intensity Strength

Measurement of magnetic strength

$B=LI$ ### Current

$I={\frac {B}{L}}$ ## Resistor in AC Circuit

### Voltage

$v_{L}=L{\frac {di_{L}}{dt}}$ ### Current

$i_{L}={\frac {1}{L}}\int {dv_{L}}{dt}$ ### Reactance

Resistance to the AC current flow

$X_{C}={\frac {v_{L}}{i_{L}}}={\frac {L{\frac {di_{L}}{dt}}}{{\frac {1}{L}}\int {dv_{L}}{dt}}}$ In frequency domain

$X_{L}(j\omega )=j\omega L$ In phasor domain

$X_{L}(\omega \theta )=\omega L\angle 90$ ### Impedance

Resistance to the AC current flow

$Z_{L}=R_{L}+X_{L}$ In frequency domain

$Z_{L}=R_{L}+j\omega L$ $Z_{C}={\frac {1+j\omega T}{R_{L}}}$ In phasor domain

$Z_{L}=R_{L}\angle 0+j\omega L\angle 90$ $Z_{L}={\sqrt {R_{L}^{2}+(j\omega L)^{2}}}\angle \omega T$ ### Time Constant

$T={\frac {L}{R_{L}}}$ ### Power

Power of the capacitor

$p={\frac {1}{2}}Li^{2}$ 