CBSE Class 6 Science Chapter 13 : Fun with Magnets NCERT Solutions

CBSE Class 6 Science 

Chapter 13 :  Fun with Magnets

NCERT Solutions

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 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.

Answer

(i) horse shoe, bar and cylindrical

(ii)  magnetic materials

(iii)  magnetic
(iv) bar magnet or lode stone

(v)  two

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 North-South direction.

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

(vii) Rubber is a magnetic material.

Answer

(i) False

(ii) True

(iii)True 

(iv) False

 (v) True

(vi) True

(vii) False.

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.

Answer

The Iron is used to make the blade in the pencil sharpener, which is getting attracted to the magnet.

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.

Answer:
N - N  Repulsion
N - S   Attraction
S - N   Attraction
S - S    Repulsion

5. Write any two properties of a magnet.

Answer:

• In magnets, the like poles attract each other and unlike poles repulse each other
• When a magnet is freely suspended, it came into rest point pointing towards North- South direction

6. Where are poles of a bar magnet located?

Answer:

The poles of a bar magnet is located at the extreme ends of the magnet.

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

Answer:

In order find the pole of the magnet, suspend the magnet freely with a thread. The side of the bar magnet, pointing towards the geographical north is the north pole of the magnet.

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

Answer:

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 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. Now we can notice that the iron strip is acting as a magnet.

9. How is a compass used to find directions?

Answer:

 A compass is usually a small box with a glass cover on it. A magnetized 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

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.

Answer:

CBSE Class 6 Science Chapter 13 : Fun with Magnets Additional Questions

CBSE Class 6 Science 

Chapter 13 :  Fun with Magnets

 Additional Questions

1. What is mean by magnetic and non-magnetic materials? Give examples
2. What happens when a magnet is freely suspended?
3. What is mean by poles of a magnet?
4. What is a compass. Which property is used in compass?
5. What are the precautions to be taken when we store magnets?
6. How we can demagnetize a magnet?
7. Give Reason: Magnets should be kept away from cassettes, mobiles, television, music system, compact disks (CDs) and the computer.

Answers

1. The materials which gets attracted towards magnets are called magnetic materials, while the objects which does not get attracted towards magnets are called non-magnetic materials. Examples of magnetic materials are iron, nickel and cobalt, where as the examples for non-magnetic materials are rubber, leather,plastic.
2. When a magnet is freely suspended, it always comes to rest in North South direction.
3. When a magnet is freely suspended, it always comes to rest in North South direction. The end of the magnet, which points North is called North pole of the magnet, while the end of the magnet, which point towards South is called South pole of the magnet.
4. Compass is small box with a glass cover on it. A magnetic 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 where we want to know the directions. Using the property of the magnets, that when a magnet is freely suspended, it always comes to rest in north-south direction.The needle of the compass indicates north-south direction when it comes to rest. It is very helpful for the travelers to know the direction.
5. To store bar magnets, it should be kept in pairs with their unlike poles on the same side. They must be separated by a piece of wood while two pieces of soft iron should be placed across their ends. To store horse-shoe magnet, a piece of iron should keep across the poles. Also magnets should be kept away from cassettes, mobiles, television, music system, compact disks (CDs) and the computer. 
6. Magnets can be demagnetized by heating, hammering and dropping from a height.
7. Cassettes, mobiles, television, music system, compact disks (CDs) and the computer etc are made up magnetic materials. Hence if we keep magnets near to it, there are chances of getting damaged. 

CBSE Class 6 Science Chapter 13 : Fun with Magnets Fill in the blanks

CBSE Class 6 Science 

Chapter 13 :  Fun with Magnets

 Fill in the blanks

1. The name magnet is named after the name of -------------, who was shepherd.
2. The freely suspended magnet always comes to rest in ---------- direction.
3. -------------- is the device used to know the direction by the travelers.
4. The magnetic force of the magnets is maximum at -------------.

Answers

1. Magnes.
2. North- South direction.
3. Compass.
4. poles.

CBSE Class 6 Science Chapter 12 : Electricity and Circuits, NCERT Solutions

CBSE Class 6 Science 

Chapter 12 :  Electricity and Circuits

 NCERT Solutions

1. Fill in the blanks :

(a) A device that is used to break an electric circuit is called _______________.

Answer:
Switch

b) An electric cell has _______________ terminals.

Answer:
Two

2. Mark  'True' or 'False' for following statements:

(a) Electric current can flow through metals.

Answer:

True

(b) Instead of metal wires, a jute string can be used to make a circuit.

Answer:

False

(c) Electric current can pass through a sheet of thermo Col.

Answer:

False

3. Explain why the bulb would not glow in the arrangement shown in Fig. 12.13.

Answer:
The bulb will not glow in this arrangement. A tester/ screw driver is connected in the circuit. Since one end of the tester/screw driver is made up of material which does not conduct electricity, the current does not passes through this circuit and hence the bulb will not glow

4. Complete the drawing shown in Fig 12.14 to indicate where the free ends of the two wires should be joined to make the bulb glow.

Answer:

5. What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them.

Answer:

Electric switch is a simple device, which is used to break or complete the circuit. Appliances like table fans, TV, radio, washing machine etc have switches built in them.

6. Would the bulb glow after completing the circuit shown in Fig. 12.14 if instead of safety pin we use an eraser?

Answer:

The bulb will not glow if we use an eraser, because eraser is an insulator which does not conduct electricity.

7. Would the bulb glow in the circuit shown in Fig. 12.15?

Answer:

In this diagram, the electric circuit is closed and the bulb will glow.

8. Using the "conduction tester" on an object it was found that the bulb begins to glow. Is that object a conductor or an insulator? Explain.

Answer:

The object is a conductor of electricity. Since the object is good conductor or electricity, the current passes through the conduction tester and the bulb glows.

9. Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.

Answer:

Rubber is an insulator, which does not allow electric current to pass through them. Hence electrician uses rubber gloves while repairing to save himself from electric shock

10. The handles of the tools like screwdrivers and pliers used by electricians for repair work  usually have plastic or rubber covers on them. Can you explain why?

Answer:

Both plastic and rubber are insulators, which does not allow electric current to pass through them. Hence the handles of the tools like screwdrivers and pliers are made with plastic or rubber to avoid electric shock.

CBSE Class 6 Science Chapter 12 : Electricity and Circuits Additional Questions

CBSE Class 6 Science 

Chapter 12 :  Electricity and Circuits

 Additional Questions

1. What are the uses of electric cells?
2. How many terminals does an electric cell have?
3. What is the structure of an electric cell?
4. Explain the structure of an electric bulb
5. Give the reason: We should not join the two terminals of the electric cell without connecting them through a switch and a device like a bulb.
6. What is the direction of the current in an electric circuit?
7. When we say that a bulb is fused? What is the reason for this?
8. What is a switch?
9. What is mean by conductors and insulators? Give examples
10. Why  do we get shock when we come in contact with electricity?
11. What are uses of conductors and insulators in day to day life?

Answers

1. Electric cells are used in torches, alarm clocks, wristwatches, transistor radios, cameras and many other devices 
2. An electric cell have two terminals. They are positive and negative terminal
3. Electric cells have a small metal cap on one side and a metal disc on other side. The metal cap is the positive terminal of the cell and the metal disc is the negative terminal. The positive and negative terminals are marked in the respective places of the cell.
4. The thin wire which glows and gives off light in the bulb is called filament. The filament is fixed to two thicker wires. The thicker wires give support to the filament. One of these thicker wires  is connected to the metal case at the base of the bulb, while the other thick wire is connected to the metal tip at the centre of the base. The base of the bulb and the metal tip of the base are the two terminals of the bulb and they are fixed in such a way that they do not touch each other.
5. If we join the two terminals of the electric cell without connecting them through a switch and a device like a bulb, the chemicals in the electric cell get used up very fast and the cell will not work.
6. The direction of current in an electric circuit is from the positive to the negative terminal of the cell.
7. We say that the bulb is fused, if it does not glow when it is connected to the cell. The main  reason for a bulb to fuse is a break in its filament, which cause the break in the path of the current.
8.  A switch is a simple device that either breaks the circuit or completes it. The switches used in lighting of electric bulbs and other devices.
9. The materials which allow electric current to pass through them are called conductors, where as the materials which does not allow electric current to pass through them are called insulators. Metals like Copper, Aluminium and Silver are examples of conductors, while glass, plastic, rubber, air wood etc are insulators.
10. We get shock when we come in contact with electricity because human body is a conductor of electricity.
11. Both conductors and insulators are useful for our day to day life. Conductors like copper is used to make wires and insulators are like plastic, rubber etc are used as wiring shields to protect us from the electric equipment.