Define mutual inductance and its effects on coupled inductors.

When two inductors are physically close to each other and have mutual inductance, they are said to be "coupled" inductors. The degree of coupling between the inductors determines the strength of the mutual inductance. This coupling is quantified by a coefficient called the coefficient of coupling, denoted by the symbol "k." The coefficient of coupling can range from 0 (no coupling) to 1 (perfect coupling).

Effects of Mutual Inductance on Coupled Inductors:

Induced Voltage: When the current in one of the coupled inductors changes, it generates a changing magnetic field around it. This changing magnetic field then links with the turns of the second inductor, inducing a voltage across its terminals. This induced voltage can either aid or oppose the change in current in the second inductor, depending on the direction of the magnetic field and the change in current.

Voltage Transformation: Mutual inductance allows for voltage transformation between the coupled inductors. If one inductor has a higher number of turns and is connected to a voltage source, the induced voltage in the second inductor can be transformed to a different voltage level, determined by the turns ratio and the coefficient of coupling.

Energy Transfer: Mutual inductance enables energy transfer between the coupled inductors. When energy is stored in the magnetic field of one inductor due to a changing current, it can be transferred to the second inductor as the induced voltage causes a current to flow. This principle is used in transformers for stepping up or stepping down voltages in power distribution systems.

Transformer Action: Mutual inductance is the basis for the operation of transformers. Transformers consist of two or more coupled inductors, where the primary coil is connected to a voltage source, and the secondary coil provides the output voltage. By controlling the turns ratio and coupling coefficient, transformers can efficiently transfer electrical energy between different voltage levels.

In summary, mutual inductance is the underlying principle behind the interaction between coupled inductors, allowing for voltage induction, energy transfer, and voltage transformation. It plays a crucial role in various applications, including transformers, inductively coupled circuits, and electromagnetic devices.