
- If an a.c. voltage is applied to an inductor the reverse voltage (back emf) generated causes the current to lag the voltage by 90°
- The ratio of voltage to current is the reactance (XL) measured on Ohms (Ω)
- XL = V ÷ I ;
I = V ÷ XL ;
V = I × XL
[V, I are rms values] - XL = 2πƒL Reactance increases with frequency