Formula for Inductance
\begin{array}{l}L=\mu N^2A/l\end{array}
Where
L = inductance in Henry (H)
μ = permeability (Wb/A.m)
N = number of turns in the coil
A = area encircled by the coil
l = length of the coil(m)
Example :
Problem 1: Compute the equivalent resistance if inductors of 5H, 2H and 7 H are linked in series?
Answer:
Known: L1 = 5H, L2 = 2H, L3 = 7H
The series inductance is articulated as
L = L1 + L2 + L3
= 5H + 2H + 7H = 14 H
Question 2: An inductor of 50 H is linked to a circuit and a frequency of 200 Hz is provided. Compute the reactance?
Solution:
Known:
Reactance X= ?,
frequency f = 200 Hz,
inductance L = 50 Henry
The reactance is articulated as
X = 2 π f L
= 2 × 3.14× 200 × 50
X= 12560 Ω