13. FUN WITH MAGNETS

---

Chapter-Reviews: 

• The substances having the property of attracting iron are now known
  as magnets.
• Magnetite is a natural magnet.
• Magnetite contains Iron. 
• Magnets, which are made from a pieces of Iron by men are known as artificial magnets. 
• Nowadays artificial magnets are prepared in different shapes. For example, bar magnet, horse-shoe magnet, cylindrical or a ballended
  magnet.
• Artificial magnet is powerful magnet than natural 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. Examples: Plastics, wood, Alumunium, leather and papers etc. 
• Magnets have two poles, that are North pole and South pole. 
• When a bar magnet hanged freely with a thread by its balanced centre point after coming in rest its one of the pole lives toward north direction while other pole lives in South direction. 
• The end of the magnet that points towards North is called its North seeking end or the North pole of the magnet.
• The other end that points towards the South is called South seeking end or the South pole of the magnet.
• All magnets have two poles whatever their shape may be.
  Usually, north (N) and south (S) poles are marked on the magnets.
• Magnet is used to separate iron contains from the mixture of sand and iron fills.
• The most of the iron filings are attracted towards the two ends of a bar magnet.
• Magnets were known to people from ancient times.
• Magnets are also used to find  the direction, such device which is used to find the direction is known as compass. 
•  

13. FUN WITH MAGNETS

---

Exericse: 

Q1: 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.

Ans: 

(i) bar-magnet, horse-shoe magnet, cylinderical magnet 

(ii) magnetic material. 

(iii) magnetic

(iv) magnet

(v) two 

Q2: 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.

Ans:

(i) False

(ii) False

(iii) True

(iv) False

(v) True

(vi) False

(vii) False  

Q3: 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: A pencil sharpener is made up of plastic and iron, where blade is magnetic material and made up of iron. 

Q4: 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.

Colomn I	Column II
N - N	___________
N - _________	Attraction
S - N	____________
________ - S	Repulsion

Ans: 

Colomn I	Column II
N - N	Repulsion
N - S	Attraction
S - N	Attraction
S - S	Repulsion

Q5: Write any two properties of a magnet.

Ans: 

(i) It attracts magnetic materials like irons, nickel and cobalt. 

(ii) Oposite poles attract each other while similar poles repel one another. 

Q6: Where are poles of a bar magnet located?

Ans: The poles of a bar magnet are located at it's both ends. 

Q7: A bar magnet has no markings to indicate its poles. How would you find out near which end is its north pole located?

Ans: When a bar magnet is hanged by its centre point i.e balanced point with a thread. When the bar magnet comes in rest its one of the pole which lives toward the north direction that is the North pole of magnet and remains is South pole. By this activity we can find the north pole of bar magnet very easily.  

Q8: You are given an iron strip. How will you make it into a magnet?

Ans: Iron strip is rubbed by one end of magnet for 30 to 40 times after that it makes into a magnet.

Q9: How is a compass used to find directions?

Ans: There are two ends in each magnetic needle are usually pained in a different colour. 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.

Q10: 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.

Column I	Column II
Boat gets attracted towards the magnet	Boat is fitted with a magnet with north pole towards its head
Boat is not affected by the magnet	Boat is fitted with a magnet with south pole towards its head
Boat moves towards the magnet if north pole of the magnet is brought near its head	Boat has a small magnet fixed along its length
Boat moves away from the magnet when north pole is brought near its head	Boat is made of magnetic material
Boat floats without changing its direction	Boat is made up non-magnetic material

Ans: The Studends do themselves. 

 

13. FUN WITH MAGNETS

---

Additional Question with Solution: 

Que: What are magnetic material?

Ans: The materials which get attracted towards a magnet are magnetic – for example,

iron, nickel or cobalt.

Que: what are non-magnetic material?

Ans: The materials which are not attracted towards a magnet are non-magnetic.

Que: Name the natural magnet.

Ans: magnetite.

Que: What are magnets?

Ans: The substances having the property of attracting iron are now known as magnets.

Que: What are artificial magnets?

Ans: The magnets are made from iron piece are known as artificial magnets.

Que: How many types are there of magnets?

Ans: there are two types of magnets.

(1) Natural magnets

(2) Artificial magnets

Que: Write the name of artificial magnets according to shape.

Ans:

(1)     Bar magnet

(2)     horse-shoe magnet

(3)     Cylindrical magnet

(4)      ball-ended magnet

Que: what are poles of magnet?

Ans: There are two ends of magnet are called its poles.

Que: How many poles are there in magnets?

Ans: There are two poles.

(1) North pole

(2) South pole

Que: What is compass?

Ans: Compass is a device made by magnet whose magnetic needles indicates the north-south direction.

Que: Write any two properties of magnet.

Ans:

(1) It attracts magnetic material like iron, nickel, and cobalt.

(2) Opposite poles of two magnets attract each other whereas similar poles repel one another.

Que: Where are poles of a bar magnet located.

Ans: The poles of a bar magnet are located at its two ends.

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

Ans: First of all we would hang the bar magnet to tie with a thread at its middle point. When it two ends remain in position of rest. The end which will be toward north that is north pole and remain is south pole.

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

Ans: Iron strip is rubbed by one end of magnet for 30 to 40 times after that it makes into a magnet.

Que: How is a compass used to find directions?

Ans: There are two ends in each magnetic needle are usually pained in a different colour. 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.

13. FUN WITH MAGNETS

---

Additional Question with Solution: 

Que: What are magnetic material?

Ans: The materials which get attracted towards a magnet are magnetic – for example, iron, nickel or cobalt.

Que: what are non-magnetic material?

Ans: The materials which are not attracted towards a magnet are non-magnetic.

Que: Name the natural magnet.

Ans: magnetite.

Que: What are magnets?

Ans: The substances having the property of attracting iron are now known as magnets.

Que: What are artificial magnets?

Ans: The magnets are made from iron piece are known as artificial magnets.

Que: How many types are there of magnets?

Ans: there are two types of magnets.

(1) Natural magnets

(2) Artificial magnets

Que: Write the name of artificial magnets according to shape.

Ans:

(1)     Bar magnet

(2)     horse-shoe magnet

(3)     Cylindrical magnet

(4)      ball-ended magnet

Que: what are poles of magnet?

Ans: There are two ends of magnet are called its poles.

Que: How many poles are there in magnets?

Ans: There are two poles.

(1) North pole

(2) South pole

Que: What is compass?

Ans: Compass is a device made by magnet whose magnetic needles indicates the north-south direction.

Que: Write any two properties of magnet.

Ans:

(1) It attracts magnetic material like iron, nickel, and cobalt.

(2) Opposite poles of two magnets attract each other whereas similar poles repel one another.

Que: Where are poles of a bar magnet located.

Ans: The poles of a bar magnet are located at its two ends.

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

Ans: First of all we would hang the bar magnet to tie with a thread at its middle point. When it two ends remain in position of rest. The end which will be toward north that is north pole and remain is south pole.

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

Ans: Iron strip is rubbed by one end of magnet for 30 to 40 times after that it makes into a magnet.

Que: How is a compass used to find directions?

Ans: There are two ends in each magnetic needle are usually pained in a different colour. 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.

Que: Which property of magnets are used by traveller to find direction during travelling? 

Ans: The magnets have a property by which It north pole indicates the North direction by suspending natural magnets with a thread. This property of magnets are used by the travellers to find the directions.  

Ques: How the traveller used magnets as compass?  

Ans: Travellers used to find directions by suspending natural magnets with a thread, north pole of magnet indicates The North direction when it comes in rest. This property of the magnet is very useful for us. For centuries, travellers have been making use of this property of magnets to find directions. Which they always carried with them.