Mutual Inductance Calculator and Formula Guide

Mutual inductance is a fundamental concept in electrical engineering, essential for understanding the interaction between two magnetic fields generated by separate coils or conductors. It describes how one coil can induce a voltage in another, enabling efficient energy transfer. On this page, you’ll find a mutual inductance calculator for quick computations and a clear explanation of the mutual inductance formula to help you understand this concept in-depth.

What is Self Inductance?

It is a property of an individual coil or inductor that quantifies its ability to oppose any change in current flowing through it. The self inductance formula is as follows.

L = (Φ/I)

Where:

• L = Self inductance in henrys (H)
• Φ = Magnetic flux linked with the coil in webers (Wb)
• I = Current flowing through the coil in amperes (A)

What is Mutual Inductance?

It describes the ability of one coil to induce an electromotive force (EMF) or voltage in another coil when they are placed close to each other and the current in one coil changes. The mutual inductance formula is as follows:

M = Φ₂ / I₁

Where:

• M = Mutual inductance in henrys (H)
• Φ₂ = It is the magnetic flux linked with the second coil due to the current in the first coil in webers (Wb)
• I₁ = Current flowing through the first coil in amperes (A)

It can also be expressed using the magnetic flux linked with the first coil as follows:

M = Φ₁ / I₂

Where:

• Φ₁ = It is the magnetic flux linked with the first coil due to the current in the second coil in webers (Wb).
• I₂ = Current flowing through the second coil in amperes (A)

Applications

Calculation of mutual inductance between two coils is useful for several reasons in the field of electronics and electrical engineering as follows:

1. It helps to predict how much voltage a change in current in one coil will induce in the other coil.
2. It is used in transformer design, coupled inductor-based filter design, and to minimize crosstalk and interference between components.
3. It is fundamental in wireless charging technologies.
4. It is used in NFC and RFID readers.
5. Accurate knowledge of mutual inductance helps in the design of antenna arrays for specific applications.

Mutual Inductance Calculator and Example

INPUTS:

• Self inductance of 1st coil = 75 mH
• Self inductance of 2nd coil = 50 mH
• Coupling factor = 0.75

OUTPUT:

• Mutual Inductance = 45.92 mH

Mutual Inductance Formula

The mutual inductance (M) between two coils can also be calculated based on their self inductances (L1 and L2) and the coupling factor (k) between them using the following formula:

M = k *√(L1 * L2)

This formula assumes ideal coupling between the coils, where all of the magnetic flux generated by one coil links with the other coil. The coupling factor, k, accounts for the actual level of coupling between the coils, which can be less than ideal due to physical separation, orientation, or other factors. If the coils are perfectly coupled (all the magnetic flux from one links with the other), k would be equal to 1.

The other mutual Inductance formula is mentioned below.

Conclusion

By mastering the mutual inductance formula and using our mutual inductance calculator, you can enhance the design and efficiency of electrical systems like transformers and inductors. Accurate calculations of mutual inductance allow for optimal energy transfer and improved circuit performance. We hope this guide and tool support your understanding and application of mutual inductance, helping you achieve reliable results in both study and practical work.