The voltage induced in a coil by a changing flux will be of such a polarity that if a current could flow as a result of that induced voltage, the flux established by that current would oppose the causing or original flux change. It is known as

Key Points

•  Lenz’s law, in electromagnetism, states that an induced electric current flows in a direction such that the current opposes the change that induced it.

Additional Information

•  Faraday’s law of induction states that “the emf induced in a circuit is directly proportional to the time rate of change of the magnetic flux through the circuit”

Mathematically;        \(E= -\frac{ϕ_{B}}{dt}\)

E → Induced EMF

ϕ_B → magnetic flux

• The Biot Savart Law is an equation describing the magnetic field generated by a constant electric current.
  • It relates the magnetic field to the magnitude, direction, length, and proximity of the electric current.
  • Biot–Savart law is consistent with both Ampere’s circuital law and Gauss’s theorem.
  • The Biot Savart law is fundamental to magnetostatics, playing a role similar to that of Coulomb’s law in electrostatics.

• Ampere’s Circuital Law states the relationship between the current and the magnetic field created by it.This law states that the integral of magnetic field density (B) along an imaginary closed path is equal to the product of current enclosed by the path and permeability of the medium.

Mathematically;     \(\oint H.dl = I_{enc}\)

H → magnetic field intensity

I_enc → Current enclosed by the path