Question

State and explain lenz law in details

Answer 1

Step 1. Statement of Lenz law.

According to Lenz's law, when an electromagnetic field is generated by a change in magnetic flux, the polarity of the induced electromagnetic field produces an induced current whose magnetic field opposes the initial changing magnetic field which produced it.

The formula of Lenz law is

$\epsilon =-N\left(\frac{d{\mathbf{\Phi }}_{\mathrm{B}}}{dt}\right)$

Where $\epsilon$ is the induced EMF, $d{\mathbf{\Phi }}_{\mathbf{B}}$ is the change in magnetic flux and $N$ is the number of turns in the coil

Step 2. Explanation

1. When a source of an electromagnetic field is connected across an inductor, a current starts flowing through it.
2. The back electromagnetic field will oppose this increase in current through the inductor.
3. To establish the flow of current, the external source of the electromagnetic field has to do some work for overcoming this opposition.