What is Magnetic Field? Video Lecture - JEE

Our topic for today is Magnetic Field.
You are late again.
Hurry up.
Something is wrong.
The region surrounding a magnet in which the force of the magnet can be experienced is called its magnetic field.
Seems like a nice spot to relax.
It's an alien ship.
We must be careful.
Run.
Take a bar magnet and keep it on a table.
Wow. Such a colorful spacecraft.
Let's go there.
Activating transparent shield.
Keep a transparent sheet on top of the
magnet.
Now, take some iron filings
and sprinkle them on the paper.
Arrange yourselves properly.
In reality, the iron filings will arrange
immediately after getting sprinkled.
The iron filings will start arranging in a
definite pattern around the magnet.
This pattern is called a magnetic field.
The lines along which the iron filings arrange are called magnetic field lines.
The magnetic field lines show the direction and strength of the magnetic field.
Magnetic field lines always start from the
north pole of the magnet and end at the south pole.
Inside the magnet, their direction is from
the south pole to the north pole.
Thus, the field lines form closed loops.
Field lines never cross or intersect each
other.
The closeness of the magnetic field lines
tells us about the strength of the magnetic field in that area.
The more closely packed lines indicate a stronger magnetic field.
Therefore, we can see more iron filings sticking at the poles.
As the lines spread out, the magnetic field
weakens.
Why did I come here?
That was the best time of my life.
You had an amazing experience.
Yes. I miss my friends.