Class VI Subject – Science Date: 09/01/2023

Topic- Lesson 13- Fun with Magnets [Workbook]

Hello students,

Please find below the answers to workbook exercises.

Q6. Answer in short
1. State different types of artificial magnets on the basis of their shapes.
Ans. different types of artificial magnets on the basis of their shapes are-
(i) Bar magnet having rectangular strip like shape
(ii) Horseshoe magnet
(iii) Cylindrical magnet
(iv) Ball ended magnet
(v) Ring shaped magnet
2. Write any two properties of a magnet.
Ans. Two properties of a magnet are-
(i) Unlike poles of a magnet, always attract each other.
(ii) A freely suspended magnet always aligns in the North-South direction.

3. A bar magnet has no markings to indicate its poles. How would you find out
near which end is its north pole located?
Ans. We will suspend the bar magnet in such a manner that it can rotate freely in a
horizontal plane. The bar magnet comes to rest in the north south direction. The end
of the magnet that points towards the geographic North is the north pole and the end
that comes to rest towards the geographic south is the south pole.

4. If a bar magnet and a piece of iron exactly similar to the bar magnet are given
to you, then how will you determine which one is a bar magnet and which one
is a piece of iron?
Ans. Repulsion is a sure test for magnetism. Due to repulsion a magnet can be tested.
Take another bar magnet and bring its North pole near both the ends of the two given
bars turn by turn. If both the ends of the bar are attracted by the bar magnet then it is
a piece of iron. If one end off the bar is attracted to the magnet and the other end is
repelled, then it is a magnet.

5. How is the magnetism of a magnet destroyed?

Ans. Magnets lose their property of magnetism due to following reasons-
(i) if they are heated,
(ii) if they are hammered,
(iii) if they are dropped from some height or
(iv) by keeping the like poles of two magnets near each other for a long time.

6. Write the principle of a magnetic compass and write its use.

Ans. Magnetic compass works on the principle- when a magnet is suspended freely it
comes to rest in a North-South direction.
Uses- It is used to find direction in aeroplanes, ships, deserts etc.

Q7. Explain giving scientific reasons.

1. Repulsion is the sure test of magnetism OR
Real test of magnetism is not attraction but repulsion.
Ans. (i) Attraction takes place between the opposite poles of two magnets as well as a
magnet and a piece of iron. So we cannot clearly state whether a given piece of metal
is iron or magnet by simply observing attraction between the two objects.
(ii) repulsion takes place between the like poles of magnets only. So if two objects
repel each other, we can surely conclude that both objects are magnets. A metal
piece shall not repel a magnet.

2. A magnetic needle is used in a magnetic compass to know the direction.

Ans. In a magnetic compass a small magnetized needle is pivoted inside the box, which
can rotate freely in a horizontal plane. When at rest, the north pole of the needle
points towards the geographic north and the south pole of the needle points towards
the geographic south. The compass is then rotated until the north and south marked
on the dial are at the two ends of the needle. Thus, we can find directions using the
magnetic compass.
Q8. Give two points of differences.

Natural Magnets Artificial magnets

1. It is made up of a stone or a piece 1. It is made from iron, nickel, steel
of rock that is magnetic. or its alloys by magnetizing them
using another magnet.
2. It has an irregular shape. 2. It has a regular shape.

Q9. Classify.
Magnetic materials – key, nickel vessel, iron, cobalt metal, pin, iron nail, needle

Non-magnetic Materials – ball pen, matchstick, copper vessel, glass, sand,

aluminium, stone

Q10. Answer the following in detail.

1. Draw the figure of a magnetic compass and explain its construction and
working.
Ans. Construction: - A compass is usually a small box made of either aluminium or
brass with a glass cover on it. A magnetized needle is pivoted inside the box,
which can rotate freely in a horizontal plane. The compass also has a circular dial
with directions marked on it.

Working: - The compass is kept at the place where we wish to know the directions.
Its needle indicates the north-south direction when it comes to rest. The compass
is then rotated until the north and south marked on the dial are at the two ends of
the needle. Thus, we can find directions at any unknown place.

2. Describe an experiment to show that unlike poles of a magnet attract each

other and like poles repel each other. Also draw the necessary figure.

Aim: to show that unlike poles of a magnet attract each other and like poles repel
each other.

Apparatus- Materials: two bar magnets, wooden stand, thin strong thread.

Procedure:
(i) Take a bar magnet.
(ii) Tie a thread at the middle of the magnet so that you may suspend it from a
wooden stand. Make sure that the magnet can rotate freely. Let it come to rest.
(iii) Now take another bar magnet.
(iv) Bring the south pole of the bar magnet held in the hand near the north pole of
the suspended magnet.
(v) Similarly, bring the north pole of the bar magnet held in hand near the south
pole of the suspended magnet.
(vi) Observe what happens in both the cases.
(vii) Now, Bring the north pole of the bar magnet held in the hand near the north pole
of the suspended magnet.
 (viii) Similarly, bring the south pole of the bar magnet held in hand near the south
pole of the suspended magnet.
(ix) Again, observe what happens in both cases.
(x) Note down your observations in the table.

Observation Table:
S. No. Pole of the suspended Pole of the bar Result
bar magnet magnet held in hand
1. North pole (N) South pole (S) Attraction
2. South pole (S) North pole (N) Attraction
3. North pole (N) North pole (N) Repulsion
4. South pole (S) South pole (S) Repulsion

Conclusion: The unlike poles (N-S and S-N) of the magnets attract each other
whereas the like poles (N-N and S-S) repel each other.

[students the same activity is also given in your journal page no. 24-25. You shall
complete the same in journal also.]

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

We shall perform the following steps to make the given strip into a magnet-
• Take a rectangular piece of iron.
• Place it on the table.
• Now take a bar magnet and place one of its
poles near one edge of the bar of iron.
• Without lifting the bar magnet, move it along the
length of the iron bar till you reach the other end.
• Now, lift the magnet and bring the pole (the
same pole you started with) to the same point of the
iron bar from which you began.
• Move the magnet again along the iron bar in the
same direction as you did before. Repeat this process
about 30-40 times.
• Bring a pin or some iron filings near the iron bar to check whether it has become a
magnet. If not, continue the process for some more time.

Activities
1. To know the position of poles in a magnet.

Apparatus-Materials: a bar magnet, iron fillings, paper

Procedure:
(i) Spread some iron filings on a sheet of paper.
(ii) Now, place a bar magnet on this sheet.
(iii) Slowly move the bar magnet on the paper.
(iv) lift the bar magnet gently away from the paper.
(v) Observe the pattern in which the iron fillings get attracted by different parts of the
magnet.
(vi) Remove the iron filings sticking to the magnet and repeat the activity.
(vii) Note down your observations.
 Observations: maximum iron fillings stick to the ends of the magnet. As you move
towards the center of the magnet the amount of iron fillings stuck to the magnet
decreases.

Conclusion: in a magnet the magnetic strength is more near the ends. These ends
are called the poles of the magnet.

2. To demonstrate that a bar magnet free to rotate in the horizontal plane always
comes to rest in North-South direction.

Apparatus-Materials: a bar magnet, wooden stand, thread

Procedure:
(i) Take a bar magnet.
(ii) Put a mark on one of its ends for identification.
(iii) Now, tie a thread at the middle of the magnet so that you may suspend it from
a wooden stand). Make sure that the magnet can rotate freely.
(iv) Let it come to rest. Mark two points on the ground to show the position of the
ends of the magnet when it comes to rest.
(v) Draw a line joining the two points. This line shows the direction in which the
magnet was pointing in its position of rest.
(vi) Now, rotate the magnet by gently pushing one end in any direction and let it
come to rest. Again, mark the position of the two ends in its position of rest. Note
your observations.

Observation: the magnet always come to rest in the same direction. This is the
north-south direction.

Conclusion: a bar magnet free to rotate in the horizontal plane always comes to
rest in North-South direction

[students the same activity is also given in your journal page no. 22. You shall
complete the same in journal also.]