Have you ever wondered, how the
electricity that powers up the lights
and charges your phone is generated?
Today we are going to learn about the
underlying concept that lights of the
entire world Electromagnetic Induction.
Let's begin by understanding what is the
magnetic field?
Magnetic field is the area around a magnet in which there is a magnetic force,
a force that attracts or repels magnetic objects.
Have a look at this figure,
crowded magnetic lines indicate a 
strong magnetic force in that area
spread out magnetic lines indicate a weak magnetic force in the area.
The direction of the magnetic field is always 
from north to south.
Let's start by making a solenoid.
A solenoid is a cylindrical coil that act as a magnet
when current passes through it.
Here we are using a PVC pipe and copper coil 
to make the solenoid.
Wrap the colored paper around the PVC pipe.
Once done wrap the copper coil around it.
Connect the ends to evive's graph pin to close the circuit.
Next select the mini oscilloscope from the menu.
You will notice that the graph is flat.
Now take a magnet and pass it through the solenoid.
You will notice a peak on the TFT screen
in a positive direction.
Now try dropping the magnet so that the 
South Pole enters the solenoid first.
You will notice that this time the graph is reversed.
Now hold the magnet stationary,
you will observe that no Peaks are generated.
This indicates that the current is generated in the coil
when the magnet moves through it.
The relative motion between the coil and the magnet induces a voltage across the coil
called the electromotive force,
which in turn generates the current.
The process of inducing an EMF in a closed circuit is called Electromagnetic Induction.
This gives us Faraday's first law.
Now let's have a look at Faraday's
second law of electromagnetic induction.
according to it the electro-motive force
generated in the circuit changes with
the change in flux linkage let's have a
look at the factors that cause d change
First, the speed of the magnet.
We have placed the coil in the center of the pipe.
Thus increasing its distance from the top.
In this case,
the speed of the magnet is more when it reaches the coil
as compared to when the coil is at the top.
You will notice the following changes.
Here we have solenoids of 100 turns, 400 turns, 
and 800 turns respectively.
You can compare the graph generated by 
the different solenoids.
Thank you for watching.
If you like this video go ahead and give it a thumbs up.
For more of such engaging videos don't forget to
subscribe to our Channel.
