Question

What is Faraday's law of electromagnetic induction?

Answer 1

Faraday's law of electromagnetic induction is a fundamental principle in physics that describes the relationship between a changing magnetic field and the induction of an electromotive force (EMF) or voltage in a closed loop of wire. It was formulated by the British scientist Michael Faraday in the early 19th century.

There are two main formulations of Faraday's law:

First Law (Faraday's Law of Induction): This law states that a change in the magnetic field within a closed loop of wire induces an electromotive force (EMF) in the wire. The magnitude of the induced EMF is proportional to the rate of change of magnetic flux through the loop. Mathematically, it can be expressed as:




=
−

Φ


EMF=−
dt
dΦ
    ​

,

where



EMF is the induced electromotive force,

Φ


dt
dΦ
    ​

 is the rate of change of magnetic flux through the loop over time, and the negative sign indicates the direction of the induced current opposes the change in magnetic flux.

Second Law (Lenz's Law): This law is a consequence of the first law and specifies the direction of the induced current. It states that the induced current will always flow in such a way as to oppose the change in magnetic flux that produced it. In other words, the direction of the induced current creates a magnetic field that counteracts the original change in magnetic field.

Faraday's law of electromagnetic induction is a key principle underlying the operation of many electrical devices, including generators, transformers, and various types of motors. It also plays a crucial role in understanding the generation and transmission of electric power. The law forms the basis for the concept of electromagnetic induction and has profound implications for our understanding of the relationship between electricity and magnetism.