First, let us see what a Magnet is
What is a Magnet
It is an object which attracts other objects like iron, steel etc
Example
- If we bring a piece of iron near a magnet, it gets attracted towards the magnet
- If we brings 2 magnets together, they also attract each other
What is a bar magnet?
A bar magnet is a rectangular magnet
It is a permanent magnet
It has two poles - North Pole and South Pole
Properties of Bar Magnet
Since bar magnet is a permanent magnet, it will have the same properties as that of permanent magnet
It's properties are
- It has two poles - North Pole and South Pole
- It attracts iron and steel particles
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Like poles repel each other, unlike poles attract each other
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When freely suspended, north pole of magnet points towards north pole of the earth
- They are permanent magnets - they do not lose their magnetism
- Magnetic field is maximum at the poles, and minimum as we go towards the center
Magnetic Field Lines in a Bar Magnet
If we sprinkle iron filings on the bar magnet, they would arrange in this form
This arrangement of iron filings is actually magnetic field lines
Which we we will study in the next post - Magnetic Field Lines
Uses of a Bar Magnet
Since bar magnet is a permanent magnet, it will have the same uses as that of permanent magnet
It's uses are
- Magnets are used in Compass
- Bar magnets are used in Fridge Magnets.
- They are used to scan the body, like in MRI (Magnetic Resonance Imaging)
Alnico and Neodymium Bar Magnet
Actually, Bar Magnet is usually of two types
- Alnico Bar Magnet - Made up of aluminium, nickel, cobalt, and iron
- Neodymium Bar Magnet - Made up of neodymium, boron, and iron
Questions
Q1 Page 224 - Why does a compass needle get deflected when brought near a bar magnet?
Q1 Page 228 - Draw magnetic field lines around a bar magnet.
Q2 Page 228 - List the properties of magnetic field lines.
Q3 Page 228 - Why don’t two magnetic field lines intersect each other?
