Inductance Formula

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.

The self-inductance in an electrical circuit is

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

Where,
voltage is V in volts,
inductance value is L,
the current is i represented by A,
time taken is t

The reactance of inductance is given by

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

Where,
Reactance is X in Henry,
the frequency is f in Hz,
Inductance is L in Henry

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

Let’s see some examples on inductance:

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 × π 200 Hz × 50 H
= 4000 Ω.