NCERT Class 6 Science Fun with Magnets

Fun with Magnets

Paheli and Boojho went to a place where a lot of waste material was piled into huge heaps. Something exciting was happening! A crane was moving towards the heap of junk. The long hand of the crane lowered a block over a heap. It then began to move. Guess, what? Many pieces of iron junk were sticking to the block, as it moved away (Fig. 13.1)! sticking to the holder. In some pencil boxes, the lid fits tightly when we close it even without a locking arrangement. Such stickers, pin holders and pencil boxes have magnets fitted inside (Fig. 13.2). If you have any one of these items, try to locatemagnets hidden in these.They had just read a very interesting book on magnets and knew immediately that there must be a magnet attached to the end of the crane that was pickingup iron from the junk yard.You might have seen magnets and have even enjoyed playing with them. Have you seen stickers that remain attached to iron surfaces like almirahs or the doors of refrigerators? In some pin holders, the pins seem to be How Magnets Were Discovered It is said that, there was a shepherd named Magnes, who lived in ancient Greece. He used to take his herd of sheep and goats to the nearby mountains for grazing. He would take a stick with him to control his herd. The stick had a small piece of 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 magnets are prepared in different shapes. For example, bar magnet, horse-shoe magnet, cylindrical or a ballended magnet. Fig.13.4 shows a few such magnets.

Activity 1

Take a plastic or a paper cup. Fix it on a stand with the help of a clamp as shown in Fig. 13.5. Place a magnet inside the cup and cover it with a paper so that the magnet is not visible. Attach a thread to a clip made of iron. Fix the other end of the thread at the base of the stand. (Mind you, the trick involved here, is to keep the length of the thread sufficiently short.) Bring the clip near the base of the cup. The clip is raised in air without support, like a kite. 

13.1 MAGNETIC AND NON-MAGNETIC MATERIALS

Activity 2 

Let us walk in the footsteps of Magnes. Only, this time, we will change the positions of the magnet and the iron. There will be a magnet at the end of our shepherd's stick. We can attach a small magnet to a hockey stick, walking stick or a cricket wicket with a tape or some glue. Let us now go out on a "Magnes walk" through the school playground What does our "Magnes stick" pick up from the school ground? What about objects in the classroom? Collect various objects of day-to-day use from your surroundings. Test these  with the "Magnes stick". You can alsotake a magnet, touch these objects with it and observe which objects stick to the magnet. Prepare a table in your notebook as shown in Table 13.1. and record your observations. Look at the last column of Table 13.1 and note the objects that are attracted by a magnet. Now, make a list ofmaterials from which these objects are made. Is there any material common in all the objects that were attracted by the magnet? We understand that magnet attracts certain materials whereas some do not get attracted towards magnet. The materials which get attracted towards a magnet are magnetic – for example, iron, nickel or cobalt. The materials which are not attracted towards a magnet are non-magnetic. What materials did you find to be nonmagnetic from Table 13.1? Is soil a magnetic or a non-magnetic material?

 Exercises 

1. Fill in the blanks in the following

(i) Artificial magnets are made in different shapes such as __________, __________ and ____________.

(ii) The Materials which are attracted towards a magnet are called________.

(iii) Paper is not a ______ material.

(iv) In olden days, sailors used to find direction by suspending a piece of ___________.

(v) A magnet always has __________ poles.

2. State whether the following statements are true or false

(i) A cylindrical magnet has only one pole.

(ii) Artificial magnets were discovered in Greece.

(iii) Similar poles of a magnet repel each other.

(iv) Maximum iron filings stick in the middle of a bar magnet when it is brought near them.

(v) Bar magnets always point towards North-South direction.

(vi) A compass can be used to find East-West direction at any place.

(vii) Rubber is a magnetic material.

3. It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic. Name a material that might have been used to make some part of it.

4. Column I shows different positions in which one pole of a magnet is placed near that of the other. Column II indica

5. Write any two properties of a magnet.

6. Where are poles of a bar magnet located?

7. A bar magnet has no markings to indicate its poles. How would you find out near which end is its north pole located?

8. You are given an iron strip. How will you make it into a magnet?

9. How is a compass used to find directions?

Please refer to attached file for NCERT Class 6 Science Fun with Magnets