Haryana State Board HBSE 6th Class Science Solutions Chapter 13 Fun with Magnets Textbook Exercise Questions and Answers.
Haryana Board 6th Class Science Solutions Chapter 13 Fun with Magnets
HBSE 6th Class Science Fun with Magnets Textbook Questions and Answers
Exercises
Question 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 magnet are called ………… .
(iii) ………… is not a magnetic material.
(iv) In olden days, sailors used to find direction suspending a piece of ………… .
(v) A magnet always has ………… poles.
Answer:
(i) bar magnet, horse-shoe magnet and round, shaped magnet
(ii) magnetic materials
(iii) leather
(iv) suspended magnet.
Question 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 magnets 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 directions at any place.
(vii) Rubber is a magnetic material.
Answer:
(i) False
(ii) True
(iii) True
(iv) False
(v) True
(vi) False
(vii) False.
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.
Answer:
A pencil sharpner is made up of iron metals-which is attracted towards the magnet. To some parts of it are made of iron/cobalt; which are magnetic materials.
Question 4. Column I show different positions in which one pole of a magnet is placed ner that of the other. Column II indicates the resulting action between them for each situation. Fill in the blanks:
Column I | Column II |
N—N | ……….. |
N—S | Attraction |
S—N | ……….. |
S—S | Repulsion |
Answer:
Column I | Column II |
N—N | Repulsion |
N—S | Attraction |
S—N | Attraction |
S—S | Repulsion |
Question 5.
Write any two properties of a magnet.
Answer:
Properties of a magnet:
1. A magnet attracts magnetic materials such as iron, cobalt and nickel towards it.
2. When a magnet is suspended freely, it stands always in North-South direction.
3. Magnetic influence can pass through a screen of cloth, plastic and papers.
Question 6.
Where are poles of a bar magnet located?
Answer:
A freely suspended magnet always:omes to rest in one direction i.e., North-South direction.
The end pint of themagnet pointing towards north is called north pole and end pointing towards south is called south pole. Thus we an see that a magnet has two poles:
(i) North-pole
(ii) South-pole.
North and South poles are marked on the magnet.
Question 7.
A bar magnet has no markings to indicate its pole. How would you find out near which end is its north pole located?
Answer:
We take a bar m agnet and tied it with a thread in the middle. Now it is suspended freely tied the thread in a stand. We find that bar magnets stay in North-South directions.
The pole which is towards north is called north pole of the bar magnet. Thus we can find the poles of a magnet.
Question 8.
You are given an iron strip. How will you make it into a magnet?
Answer:
Method of making an iron strip , a magnet: Take the iron strip and place it on the table. Strike it with one pole of a bar magnet in one direction. When you reach the other end of the iron stick, leave the magnet and bring the same pole back to the starting end of the iron stick. Strike again in the same direction. Repeat this process about 30-40 times. Check whether the iron piece has now become a magnet. If not, continue the process for some more time. Remember that the pole and the direction of the magnet is not to be changed. In this way, an iron stick can be converted into a magnet. (See Fig. 13.3.)
Question 9.
How is a compass used to find directions?
Answer:
A compass is made on the property of a magnet, staying in north-south direction. This is a small glass case containing a magnetised needle pivoted on a nail. The needle can rotate freely. Whenever it is kept, its needle always rests in north-south direction, (See Fig. 13.4.)
Normally the north pole of the needle is painted red or some other indication is given to identify north and south poles. So using this needle, north and south can be identified.
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.
Column I | Column II |
(A) Boat gets attracted towards magnet. | (a) Boat is fitted with a magnet with north pole toward its head |
(B) Boat is’not affected by the magnet. | (b) Boat is fitted.with a magnet with south pole towards its head |
(C) Boat moves towards the magnet if | (c) Boat has a small megnet fixed along its north pole of the magnet is brought length. near its head. |
(D) Boat moves away from the magnet when north pole is brought near its boat. | (d) Boat is made of magnetic material. |
(E) Boat floats without changing its attraction. | (e) Boat is made up non-magnetic material. |
Answer:
(A)-(d).
(B)—(c).
(C)—(b)
(D)—(a),
(E)—e).
HBSE 6th Class Science Fun with Magnets Important Questions and Answers
Very Short Answer Type Questions
Question 1.
Name two places where magnets are used in your daily life.
Answer:
(1) Refrigerators
(2) Small pencil box.
Question 2.
Why do chess pieces stick to metallic card board?
Answer:
Because chess pieces are fitted with magnets.
Question 3.
What was the name of Greek shephered?
Answer:
His name was Magnes.
Question 4.
Magnetic ludo is not displaced with movement of vehicle. Why?
Answer:
Because the ludo is fitted with magnet.
Question 5.
From what materials magnets are made of?
Answer:
Magnets are made of from magnetic materials. .
Question 6.
Name two magnetic materials.
Answer:
(i) Iron
(ii) Cobalt.
Question 7.
Which, from the following objects, are attracted towards magnet?
Iron ball, plastic scale, wood stick, glass strip, pins.
Answer:
Iron ball and pins are attracted towards magnet.
Question 8.
What are non-magnetic materials?
Answer:
Materials which do not attract towards magnets are called non-magnetic materials.
Question 9.
Name some non-magnetic materials.
Answer:
Leather, plastic, cloth and paper etc.
Question 10.
What is a magnet?
Answer:
A magnet is an object which attracts pieces of iron, cobalt and nickel.
Question 11.
What happens when the north pole of a magnet ip brought near the north pole of a freely suspended magnet?
Answer:
They repel each other.
Question 12.
What happens when the north pole of a magnet is brought near the south pole of a freely suspended magnet?
Answer:
They attract each other
Question 18.
Can we have an isolated north pole or south pole?
Answer:
We cannot have an isolated north pole or south pole. They always exist in opposite direction.
Question 14.
Which iron is used for making a permanent magnet?
Answer:
Hard steel and alloys.
Question 15.
Which iron is used for making a temporary magnet?
Answer:
Soft iron.
Question 16.
Why are artificial magnets preferred to natural magnets?
Answer:
Artificial magnets are very strong in comparison with natural magnets.
Question 17.
In which direction does a freely suspended bar magnet come to rest?
Answer:
North-South direction.
Question 18.
Why does a magnetic needle get deflected when placed near a current carrying conductor?
Answer:
Due to magnetic field produced by current.
Question 19.
A bar magnet attracts iron fillings more strongly at two ends. What are these ends points called?
Answer:
These end points of the bar magnet are called its poles.
Question 20.
Name two devices where electromagnets are used?
Answer:
Electric bell and loud-speaker.
Question 21.
What type of magnet is used in an electric bell?
Answer:
U-shaped magnet is used in an electric bell.
Question 22.
What is the instrument in which directive property of a magnet is used?
Answer:
Mariner’s compass.
Question 23.
What is a temporary magnet?
Answer:
A magnet which retains its properties of magnet for a short time period is called temporary magnet.
Question 24.
How is a magnet demagnetised?
Answer:
(i) By heating
(ii) by hammering the magnet violently.
Question 25.
Two like poles of magnets are brought near each other. Will they attract or repel each other?
Answer:
They will repel each other.
Question 26.
What is a natural magnet?
Answer:
A natural magnet is a naturally occuring ore of iron which has attractive and directive property.
Question 27.
Can we have a magnet with a single pole?
Answer:
No, because unlike poles of equal strength exist together.
Question 28.
What is a sure test of magnetism?
Answer:
Repulsion is a sure test of magnetb.m.
Short Answer Type Questions
Question 1.
What is the difference between a temporary magnet and a permanent magnet?
Answer:
Temporary magnet | Permanent magnet |
1.It loses its magnetic power as soon as the source of magnetism removed. | 1. It remains magnet even after the source of magnetism is removed. |
2. It is made from soft iron. | 2. It is made from steel. |
3. In it the domain point in the same direction only for short time interval. | 3. In it the domains point in the same direction permanently. |
Question 2.
Give two applications of electromagnets.
Answer:
(i) They are used in cranes to lift heavy loads of scrap iron and iron sheets.
(ii) They are used to separate magnetic substances from non-magnetic substances.
Question 3.
What are the properties of a magnet?
Answer:
There are two main properties of a magnet:
(i) Attractive property.
(ii) Directive property.
Question 4.
Define attractive and directive property of a magnet.
Answer:
(i) Directive property: On suspanding a bar magnet freely with a thread we find that at rest it always points towards north- south direction.
(ii) Attractive property: Magnet has the property to attract iron, cobalt and nickel towards it. These substances are called magnetic substances.
Question 5.
How will you distinguish two identical bars of iron as a permanent magnet and an ordinary piece of iron?
Answer:
To identify the real magnet bring a third magnet near each end of the identical bars. In case of ordinary bar, both its end should be attracted towards magnet. But in case of a permanent magnet, one of its ends would be repelled.
Question 6.
What is the difference between the magnetic properties of soft iron and steel?
Answer:
Magnetic properties of soft iron | Magnetic properties of steel |
1. It gets strongly magnetised when magnetised by induction, | 1. Steel is feebly magnetised when magnetised by induction. |
2. Soft iron can be demagnetised very easily, hence electromagnets are made of soft iron. | 2. Steel cannot be demagnetised easily, hence permanent magnets are always made of steels. |
Question 7.
Explain that induction precedes attraction.
Answer:
When iron piece is brought near a magnet, the iron is first temporarily magnetised by induction. Thus being two opposite poles, there is attraction. The iron piece first converts into a magnet having opposite poles, near its magnetised pole. Thus induction precedes attraction.
Question 8.
What is the difference between an electromagnet and a magnet?
Answer:
A magnet is a natural magnet with fixed magnetic effects. It is obtained from nature in the form of mineral. An electromagnet is a soft iron piece which shows magnetic effects only when eletric current is passed through it. Its magnetic effects can be increased or decreased by increasing electric current through conducting wire round the core.
Question 9.
What is a magnetic compass? What are its uses?
Answer:
A magnetic compass is a device which has a magnetic needle which is free to move on a pivot at the centre of a round box. It is used by sailors and navigators to find the directions. The compass needle is free to rotate and aligns in the north-south direction. Its free end that points north is marked red. (See Fig. 13.4.).
Long Answer Type Questions
Question 1.
What is a compass? Describe the construction of a compass with the help of a labelled sketch. How is a compass used to find directions?
Answer:
The compass is an instrument to find the directions of a place. The compass has a tiny magnet in the form of a needle which can rotate freely on a pivot (or pin). The pivoted magnetic needle of the compass is enclosed in a small brass box having a glass top. The compass has a circular dial with various directions marked on it. The needle of compass always conies to rest along the north-south directions. The north pole of compass needle is painted with different colour to distinguish it from the south pole.
In order to find the directions at a place, the compass is kept on a flat surface at that place. The needle of compass will soon come to rest along the north-south direction. The compass is then rotated until the painted end of needle is towards N (North) mark on the dial and the other end of needle is towards S (South) mark on the dial. We can now find any direction by looking at the dial of the compass.
Fun with Magnets Class 6Â HBSE Notes
- Some materials such as magnetite show magnetic properties. These are called natural magnets.
- Magnet attracts some materials such as iron, cobalt, nickel. Such materials are called magnetic materials.
- The materials such as paper, cloth, leather etc. which are not attracted towards magnets are called non-magnetic materials.
- Magnetic attraction is maximum near the ends of the magnet. These ends are called magnetic poles.
- When suspended freely, a magnet always aligns in N—S direction.
- When suspended freely one pole of the magnet always points towards North. This is known as North pole.
- The other pole which points towrds South, is known as South pole.
- Opposite poles of two magnets attract each other whereas there is repulsion between similar poles.
- Magnetic influence can pass through screens of some substances like cloth, plastic, paper, glass etc.
- While travelling on the sea or air, a magnet can be used to find the directions. In olden days sailors used this property of magnet for finding directions when they were at sea.
- Compass is a small glass case, containing a magnetised pivoted on a nail. The needle can rotate freely.
- Wherever it is kept its needle always rests in North-South direction.
- On heating, or hammering magnetic property is destroyed.
- To keep it safe, store bar magnets in pairs with unlike poles together, separated by a bit of wood and two pieces of soft iron across the ends. For horse-shoe magnet, keep one iron piece across the poles.