Factors Affecting Inductance: Their Effects, How to Calculate?

Inductance is a fundamental concept in electrical engineering and physics, and it is defined as the ability of a coil of wire to store energy in a magnetic field. This property is essential in many electrical circuits and devices, including transformers, motors, and generators. However, inductance is not a constant value and can be affected by a variety of factors, such as the number of turns in the coil, the material used for the wire, and the shape of the coil. In this article, we will explore the different factors that can affect inductance and how they influence the behavior of electrical circuits.

Factors Affecting Inductance

Factors Affecting Inductance are:

The number of turns (N) for the coil

More turns for a coil will produce a stronger magnetic field resulting in a higher induced voltage and inductance.

The length of the core (l)

A longer core will make a loosely spaced coil and a longer distance between each turn, therefore producing a weaker magnetic field resulting in a smaller inductance.

The cross-section area of the core (A)

A larger core area requires more wire to construct a coil, and therefore it can produce a stronger magnetic field resulting in a higher inductance.

The permeability of the material of the core (μ)

A core material with higher permeability will produce a stronger magnetic field resulting in a higher inductance. (Permeability of the material of the core determines the ability of the material to produce a magnetic field. Different materials have different degrees of permeability.) Factors affecting the inductance of an inductor are illustrated in Figure:

Where inductance is symbolized by L, measured in henries (H); area of the core is symbolized by A, measured in m²; permeability is symbolized by μ; the number of turns is symbolized by N.

From the expression of the factor affecting inductance, we can see that either when the number of turns of a coil increases, or when the cross-section area of the core increases, or when core material with higher permeability is chosen, or when the length of the core is reduced, the inductance of an inductor will increase.