Class 6 || Science || Ch. 13. Fun with magnets

Class 6 || Science || Ch. 13. Fun with magnets

Q. 1. What is the magnet? What are main types of magnets? 

Ans. A magnet is an object which can attract iron, Cobalt and nickel. 

Magnets are of two types 

1. Natural magnets and 2. Srtificial magnet or man made magnets 

1. Natural magnets,:-  The magnets find in nature, naturally is called natural magnets for example magnetite.

2. Artificial magnets or man made magnets :- Magnets prepared artificially from iron is called artificial or man made magnets.

Q. 2. What are the poles of magnets ? How many poles of a magnet have?

Ans. The ends of magnets are called the poles of magnets. 

A magnet have two poles, North pole and South pole 

North pole :- Which end of magnet points towards north is called its North seeking end or north pole of the magnet.

South pole :- Which end of magnet points towards South is called its South seeking end or South pole of the magnet.

Q. 3. What is material or substance ? What are main types of the substance on the base of magnetic property?

Ans. Anything else which finds in nature is called substance or materials. There are two types of the materials on the basis of the magnetic property, 1. Magnetic material and 2. Non magnetic materials.

1. Magnetic materia:- Materials which get attracted towards a magnet are called magnetic materials, iron, Cobalt and nickel are example of diamagnetic materials. 

2. Non magnetic materials:- Materials which do not get attracted towards a magnet are called non magnetic materials, water, plastic, paper, would etc are example of the non magnetic materials.

* A freely suspended magnet always aligns in North and South direction.

* Opposite poles of two magnets attract each other whereas similar poles repel one another.

Q. 4. How can you find the direction with the help of a bar magnet?

Ans. The needle of a bar magnetic compass always suspended towards the North−South direction. If the North−South direction is known, then the East−West direction can also be determined which is perpendicular to the compass needle.

Exercise

Q. 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 magnets 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.

Ans.

(i) bar magnets, horse-shoe magnets and cylindrical magnets

(ii) magnetic materials.

(iii) magnetic

(iv) bar magnet

(v) two

Q. 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 the North−South direction.

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

(vii) Rubber is a magnetic material.

Answer.

(i) False; A magnet of any shape always has two poles: north pole and south pole.

(ii) False; Natural magnets were discovered in Greece.

(iii) True

(iv) False; Maximum iron filings stick at the two ends of the magnet as the magnetic strength is maximum at the ends or poles of a magnet.

(v) True

(vi) True

(vii) False; Rubber does not get attracted by a magnet. Therefore, it is not a magnetic material.

Q. 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.

Ans. :- The blade of a pencil sharpener is made up of iron which is a magnetic material. Due to this a pencil sharpener gets attracted towards both poles of a magnet.

Q. 4. Column I shows different positions in which one pole of a magnet is placed near the other. Column II indicates the resulting action between them for each situation. Fill in the blanks.

Column I         Column II

N − N               _________

N − __              Attraction

S − N               _________

__ − S             Repulsion

Ans. :- We know that the like poles of a magnet repel each other whereas the unlike poles attract each other. So, given blanks can be filled as follows:

Column I     Column II

N − N            Repulsion

N − S            Attraction

S − N            Attraction

S − S             Repulsion

Q. 5. Write any two properties of a magnet.

Ans. Two properties of a magnet are:

(i) A magnet always has two poles: north pole and south pole.

(ii) Like magnetic poles repel each other and unlike magnetic poles attract each other.

Q. 6. Where are the poles of a bar magnet located?

Ans. Poles of a bar magnet are located at its two ends.

Q. 7. A bar magnet has no markings to indicate its poles. How can you find out the location of the north pole?

Ans. After suspending it freely the location of the poles of as magnet can be determined. A freely suspended bar magnet always points in north−south direction. The end that points towards north direction is the north pole of the magnet and the other one end that points towards south direction is the south pole of the magnet.

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

Ans. An iron strip can be converted into a magnet by following method:

Place the iron strip on a table. Place one pole of a bar magnet near one end of this iron strip. 

Dragged the bar magnet along the strip starting from one end to the other end. Repeat this process again and again so many times. The iron strip will converte into a bar magnet with two poles.

Q. 9. How is a compass used to find directions?

Ans. A compass has a magnetic needle that always suspended towards the North−South direction. Red arrow of the compass needle is termed as north pole and the other end as south pole. If the North−South direction is known, then the East−West direction can also be determined which is perpendicular to the compass needle.

Q. 10. A magnet was brought from different directions towards a toy boat that has been floating on water in a tub. The effect observed in each case is stated in Column I. Possible reasons for the observed effects are mentioned in Column II. Match the statements given in Column I with those in Column II.

Column I

Column II

1. Boat gets attracted towards the magnet

A. Boat is fitted with a magnet with the north pole towards its head

2. Boat is not affected by the magnet

B. Boat is fitted with a magnet with the south pole towards its head

3. Boat moves towards the magnet when the north pole of the magnet is brought near its head

C. Boat has a small magnet fixed along its length

4. Boat moves away from the magnet when the north pole is brought near its head

D. Boat is made of magnetic material

5. Boat floats without changing its direction

E. Boat is made of a non-magnetic material

Answer.

1. D,.  2. E,. 

Column I

Column II

1. Boat gets attracted towards the magnet

D. Boat is made of a magnetic material

2. Boat is not affected by the magnet

E. Boat is made of a non-magnetic material

3. Boat moves towards the magnet when the north pole of the magnet is brought near its head

B. Boat is fitted with a magnet with the south pole towards its head

4. Boat moves away from the magnet when the north pole is brought near its head

A. Boat is fitted with a magnet with the north pole towards its head

5. Boat floats without changing its direction

C. Boat has a small magnet fixed along its length