What does the term "Coefficient of Coupling" refer to in a mutual inductance transformer?

The term "Coefficient of Coupling" refers to the measure of the effectiveness with which magnetic flux from one coil links to another coil in a mutual inductance transformer. It is represented as a numerical value between 0 and 1, or expressed as a percentage, indicating the fraction of the magnetic field produced by one coil that effectively couples to the other coil.

When considering the options, the coefficient of coupling is primarily concerned with the percentage of magnetic flux lines that link the two coils compared to the total magnetic flux produced. A higher coefficient indicates that a larger proportion of the magnetic field from one coil interacts with the other, resulting in increased efficiency in energy transfer.

This concept is foundational in transformer design and operation, influencing factors like efficiency, performance, and the design of the winding configuration to ensure effective coupling.