Fun with Magnets | Science 6th | Chapter 13 | Questions and Answers

JANDKNCERT | Science 6^th |

Fun with Magnets | Science 6th | Chapter 13 | Questions and Answers

 

Chapter 13: Fun with Magnets

Dear Students, in Chapter 12, you learnt about the Electricity and Circuits, in which you learnt about the dry cell and its positive and negative terminals, circuits, objects that allow the current to pass through them, that is, conductors, and the objects that do not allow the current to pass through them, that is, insulators, for example, aluminium, copper, nickel are conductors while as rubber, plastic, wood etc. are insulators. Switches are safety devices.

 

In this chapter, you will learn about the Fun with Magnets. The following points will help you to understand this chapter easily.

·    Magnetite is a natural magnet.

·    The magnet attracts materials like iron, nickel, cobalt. These are called magnetic materials.

· Materials that are not attracted towards magnet are called non-magnetic.

·      Each magnet has two magnetic poles—North and South.

·    A freely suspended magnet always aligns in N-S direction.

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

Let us try to answer some questions taken from the NCERT Book of Science Class 6th. This Exercise is taken from the same book.

Exercises

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.

vi. A compass helps in determining the direction of _________.

vii. Magnetic _______ exists in pairs.

viii. Like poles of magnet ___ each other.

 

Answer.

i. Artificial magnets are made in different shapes such as bar magnet, horseshoe magnet and cylindrical magnet.

ii. The materials which are attracted towards a magnet are called magnetic materials.

iii. Paper is not a magnetic material.

iv. In the olden days, sailors used to find direction by suspending a piece of the natural magnet with a thread.

v. A magnet always has two poles.

vi. A compass helps in determining the direction of the north pole.

vii. Magnetic poles exist in pairs.

viii. Like poles of a magnet repel each other.

 

 

Q2. State whether the following statements are true or false

 

i. A cylindrical magnet has only one pole. False

ii. Artificial magnets were discovered in Greece. False

iii. Similar poles of a magnet repel each other. True

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

v. Bar magnets always point towards the North-South direction. True

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

vii. Rubber is a magnetic material. 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.

 

Answer.

A pencil sharpener has a metal blade inside it. Since the metallic blade is a magnetic material hence the pencil sharpener got attracted by both poles of a magnet.

 

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.

 

Colum I	Column II
N-N	___________
N- ______	Attraction
S-N	_________
_______-S	Repulsion

 

Answer.

 

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

 

 

Q5. Write any two properties of a magnet.

 

Answer.

(i) A magnet attracts metallic materials like iron, nickel etc.

(ii) It helps in finding the directions.

 

Q6. Where are poles of a bar magnet located?

 

Answer.

Poles of a bar magnet are located towards the region close to its two 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?

 

Answer.

We can find out the north pole of a bar magnet by the following steps:

Step 1: Tie a thread at the middle of the bar magnet and suspend it from a wooden stand.

Step 2: Mark the two points and rotate them two to three times after every time it comes to rest.

Step 3: You will observe that the magnet rests in the same direction after every rotation.

Step 4: Use the direction of the rising sun in the morning. If you face towards the east then you can easily find out the north pole of a magnet towards your left.

Remember, a bar magnet always shows North-South direction.

 

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

 

Answer.

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

(i) Take a rectangular strip of iron and place it on the wooden table.

(ii) Place one end of bar magnet on the iron strip and drag it along length of the iron strip from

one end to another.

(iii) When you reach the end lift the magnet and bring the same pole of magnet back to the

starting end of the iron strip and repeat the above process.

(iv) Repeat the process about 30-40 times.

(v) Bring an iron pin or iron fillings near the iron bar to check whether it has become magnet. If not, continue the process of striking for some more time.

(vi) The pole of the magnet or direction of striking should not change.

(vii) Finally, the iron bar will be converted to magnet.

 

Q9. How is a compass used to find directions?

Answer.

To find directions, the compass is kept at the place where we wish to know the directions. It consists of a magnetised needle, which indicates the north-south direction when it comes to rest. It is then rotated until 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 effects are mentioned in Column II. Match the statements given in Column I with those in Column II.

 

Column I	Column II
The boat gets, attracted towards the magnet	The boat is fitted with a magnet with the North Pole towards its head.
The boat is not affected by the magnet	The boat is fitted with a magnet with the South Pole towards its head.
The boat moves towards the magnet if the North Pole of the magnet is brought near its end.	The boat has a small magnet fixed along its length.
The boat moves away from the magnet when the North pole is brought near its end.	The boat is made of magnetic material.
The boat floats without changing its direction.	The boat is made of non-magnetic material.

 

Answer.

Column I	Column II
The boat gets attracted towards the magnet	The boat is made of magnetic material.
The boat is not affected by the magnet	The boat is made of non-magnetic material.
The boat moves towards the magnet if the North Pole of the magnet is brought near its end.	The boat is fitted with a magnet with the South Pole towards its head.
The boat moves away from the magnet when the North pole is brought near its end.	The boat is fitted with a magnet with the North Pole towards its head.
The boat floats without changing its direction.	The boat has a small magnet fixed along its length.