Magnetic Field Behaviour in Single Coil

         Lenz’s law is normally associated with determining the direction of an electric current that has been induced by electromagnetic induction. It is a law which is seen to be closely connected with the law of conservation of energy, even though it relates to scenarios that involve non-conservative forces. These non-conservative forces will always encounter an inertial resistance which has to be overcomed. In overcoming this inertial resistance, energy is always used up in equal amount to the new energy that has been created. Lenz’s law is therefore not restricted to electromagnetic induction. It applies equally to linear polarization, capacitor circuits, and to matters relating to changes in linear momentum. Newton’s laws of motion are a mechanical manifestation of Lenz’s law. The direction of current is defined by the right hand thumb rule.

        The type of magnetic field generated due to DC and AC current and the fields generated when the direction of current is reversed during DC voltage supply is illustrated through this experiment. When the current is reversed, the shifting of poles is also observed. While applying AC current , the change in the magnetic field pattern due to frequency change can also be studied.

Let us take a simple example.

Let us assume a field given by the equation I=Io cos 2.pi.50t

The result will be a pulsating sine wave as shown in the following link.