# Inductance Formula

The property of a conductor by which an alteration in current passing through it creates (induces) voltage or electromotive force in any nearby conductors (mutual inductance) and in both the conductor itself (self-inductance) is termed as Inductance Inductance is described as opposing of changes of current. The inductance value is represented as L and its unit is Henry. One Henry value is equivalent to the induced one volt by changing of current in one ampere per second in an inductance value. The inductance value is of two types. One is mutual inductance and another one is self-inductance. Let us see the applications of inductance value.

Fomula for Inductance is given by

$L=\mu N^{2}A/l$
Where
L= inductance in Henry (H)
$\mu$ = permeability (Wb/A.m)
N= number of turns in the coil
A= area encircled by the coil ($m^{2}$)
l= length of the coil(m)
The voltage induced in a coil, ( V)  with an inductance of L is given by

$V\,&space;=\,&space;L\,&space;\frac{di}{dt}$

Where,
voltage is V (volts)
inductance value is L
the current is I ( A)
time taken (t)

The reactance of inductance is given by

$X\,&space;=\,&space;2\,\pi&space;fL$

Where,
Reactance is X in ohm (Ω)
the frequency is f in Hz,
Inductance is L in Henry (H)

The total series inductance is

$L\,&space;=\,&space;L_{1}+L_{2}+L_{3}+\,&space;.....+L_{n}$

The parallel inductance is

$\frac{1}{L}\,&space;=\,&space;\frac{1}{L_{1}}+\frac{1}{L_{2}}+.......+\frac{1}{L_{n}}$

Where, L1, L2, L3….. Ln  are the inductance values.

## Inductance – Solved Examples

Problem 1: Compute the equivalent resistance if inductors of 5H, 2H and 7 H are linked in series?

Known: L1 = 5H, L2 = 2H, L3 = 7H
The series inductance is articulated as
L = L1 + L+ 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= 12560Ω

#### 1 Comment

1. Johnkenedy mbonu

How to calculate inductance