Class 6 - Physics - Fun with Magnets

Question1.

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.

(i) Artificial magnets are made in different shapes such as bar-magnet, cylindrical magnet and horse-shoe magnet.

(ii) The Materials which are attracted towards a magnet are called magnetic material.

(iii) Paper is not a magnetic material.

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

Question2.

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.

• A cylindrical magnet has only one pole- False

Explanation:

Poles always exist in pairs in a magnet.

• Artificial magnets were discovered in Greece- False

Explanation: -

Natural magnets were discovered in Greece.

• Similar poles of a magnet repel each other- True

Explanation:-

Like poles repel each other and unlike poles repel attract each other.

• Maximum iron filings stick in the middle of a bar magnet when it is brought near them-False

Explanation:-

Maximum iron fillings will stick to the ends of the bar magnet because at the ends of the magnet poles are located.

The strength of the poles is maximum at the ends of the magnet.

• Bar magnets always point towards North-South direction-True

Explanation:-

A freely suspended magnet always aligns itself in North-South direction.

• A compass can be used to find East-West direction at any place- True

Explanation: -

Always the needle of the compass points towards North-South direction. So if North-South direction is known then East-West direction can also be known.

• Rubber is a magnetic material-False

Explanation: -

Rubber is an insulator. It cannot be attracted or repelled by a magnet.

Question 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.

The blade of sharpener is made up of iron.

Iron is a magnetic material because of this pencil sharpener gets attracted by the poles of a magnet although the body is made up of plastic.

Question 4.

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

Column II indicates the resulting action between them for each situation. Fill in the blanks.

Like magnetic poles repel each other, while unlike magnetic poles attract each other.

Question 5.

Write any two properties of a magnet.

1. Magnets have two poles i.e. North Pole (N) and South Pole(S).
2. A freely suspended magnet always aligns in N-S direction

Question 6.

Where are poles of a bar magnet located?

The poles (north and south) of bar magnet are located at extreme ends of the bar magnet.

Question 7.

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

Tie a bar magnet to a thread and suspends it freely. When suspended freely it will always align itself in north-south direction.

So the end that points to the north direction will be considered as the north pole of the magnet and the end

which points to the south direction will be its south pole.

Question 8.

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

“Touch and Stroke” method is used to make an iron strip into a magnet.

1. Take a rectangular piece of iron bar.
2. Take a bar magnet and keep in contact with one of its poles with one edge of the bar of iron.
3. Without lifting the bar magnet, move it along the length of the iron bar till you reach the other end.
4. Lift the magnet and bring the pole (the same pole you started with) to the same point of the iron bar from which we began.
5. Move the magnet again along the iron bar in the same direction as you did before.
6. Repeat this process about 30-40 times.
7. Bring few all pins near to the iron bar and check if it is converted to a magnet or not.

Question 9.

How is a compass used to find directions?

A compass is usually a small box with a glass cover on it. A magnetised needle is pivoted inside the box, which can rotate freely.

The compass also has a dial with directions marked on it.

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.

To identify the north-pole of the magnetic needle, it is usually painted in a different colour.

Red colour arrow usually points to North Pole. If we know the North direction we can find all other 3 directions of that place.

Question 10.

A magnet was brought from different directions towards a toy boat that has been floating in water in a tub.

Affect observed in each case is stated in Column I. Possible reasons for the observed affects are mentioned in Column II.

Match the statements given in Column I with those in Column II.

1. Magnet materials get attracted towards a magnet.
2. Non-magnetic materials do not get attracted towards a magnet.
3. Unlike poles of magnets attract each other.
4. Like poles of magnets repel each other.
5. Magnets always point towards North-South direction.
6. Unlike poles attract each other.
7. Like poles repel each other.