Mutual inductance is a fundamental concept in electromagnetism that describes the interaction between two adjacent electrical circuits through magnetic fields. When a changing current flows through one circuit, it creates a time-varying magnetic field around it. This varying magnetic field, in turn, induces a voltage in the second circuit, known as the "mutually induced voltage."
The mutual inductance (M) between the two circuits is a measure of this induced voltage per unit of changing current in the first circuit. It is measured in henrys (H). Mathematically, the mutual inductance between two circuits can be expressed as:
M = (N2 * Φ21) / I1
where:
M is the mutual inductance in henrys (H).
N2 is the number of turns in the second circuit's coil.
Φ21 is the magnetic flux linkage between the two circuits, which is the magnetic flux (φ) produced by circuit 1 that passes through the coils of circuit 2.
I1 is the current flowing through the first circuit.
Mutual inductance is essential in various applications, especially in transformers, where it allows for the efficient transfer of electrical energy from one circuit to another. It is also relevant in various other devices and systems, such as mutual inductance sensors and electromagnetic coupling in communication systems. Understanding mutual inductance is crucial for designing and analyzing many electrical and electronic circuits and devices.