CBSE NCERT Class VI (6th) | Science | Physics
Chapter : Fun With Magnets
CBSE NCERT Solved Question Answer
Q1 How were magnets discovered?
A1 There was a Shepard named Magnes who lived in ancient Greece .He used to take his herd of sheep and goats to the mountains for grazing He would take a stick with him to control his herd the stick had iron attached at one end. One day he was surprised to find that he had to pull hard to free his stick from a rock on the mountains. It seemed if the stick was being attracted by the rock. The rock was a natural magnet.
Q2 What is magnetite?
A3 Magnets are substances having property of attracting iron or iron like materials.
Q4 Name some different shapes of magnets.
1. Bar magnet
2. horse shoe magnet
3. cylindrical magnet
4. ball ended magnet
5. needle magnet
Q5 What are magnetic and non magnetic materials?
A5 The materials which get attracted to magnets are known as magnetic materials example: iron nickel cobalt. The materials which do not get attracted to magnets are known as non magnetic materials example plastic rubber wood.
Q6 Demonstrate what happens when we move a bar magnet through iron filings (draw the diagram also)
A6 When we move bar magnet through iron filings they get attracted to magnet. Minimum iron filings get attached to the centre region and maximum iron filings get attached to the end regions of bar magnet which is known as the poles showing the attraction is maximum at the poles.
Q7 How many poles exist in a magnet?
A7 Every magnet has two poles north pole and a south pole. North Pole is denoted by N and South Pole is denoted by S
Q8 What is the property of magnet which is used by travelers to find directions?
A8 When we freely suspend a magnet it always points in N-S direction This property is used by travelers to find directions
Q9 What is a magnetic compass?
A9 A device which was developed based on the property of magnets of finding directions is known as magnetic compass.
A compass is usually a small box with glass cover on it A magnetized needle is pivoted inside the box which can rotate freely The compass also has a dial with directions marked on it Its needle indicates north south directions when it comes to rest.
Q10 How can you prepare your own magnet?
A10 We can prepare magnet by the following processes
a) By rubbing one pole without lifting 20-30 times on an iron nail or iron strip.
b) By passing current through an iron nail or iron strip we obtain a magnet and this magnet is known as electromagnet.
Q11 what happens when we bring like poles of a magnets close to one another?
A11 Like poles repel.
Q12 what happens when we bring unlike poles of a magnets close to one another?
A12 Unlike poles attract.
Q13 How do magnets lose their properties?
A13 Magnets loose their property if they are heated, hammered or dropped from some height.
Q14 How can we keep our magnets safe?
A14 To keep magnets safe Bar magnets should be kept in pairs with unlike poles on same side They must be separated by a piece of wood while two pieces of soft iron should be placed across their ends For horse shoe magnet one should keep a piece of iron across the poles.
Q15 what precautions should be taken in handling magnets?
A15 We should keep magnets away from cassettes, mobiles, TV music systems compact disks and computers.