Exploring Magnets Class 6 Questions and Answers NCERT Solutions
Class 6 Science Chapter 4 Exploring Magnets Question Answer
Intext Questions
(Page no. 62)
Question 1.
Do magnets stick to objects made of certain materials only?
Answer:
Yes, magnet attracts certain materials whereas some do not get attracted towards magnet. The materials which get attracted towards a magnet are magnetic e.g. iron, nickel, cobalt etc. The materials which are not attracted towards a magnet are non-magnetic. In their natural states, metals such as aluminium, brass, copper, gold, lead and silver do not attract magnets.
(Page no. 64)
Question 2.
Do all parts of a magnet attract magnetic materials equally?
Answer:
No, all parts of a magnet do not have equal magnetic strength. In a bar magnet, the magnetic field around the poles is stronger than the middle part, where the magnetic field is weaker. Also in case of horseshoe magnet, the magnetic strength is higher near the poles.
(Page no. 65)
Question 3.
Can we find a magnet with a single pole?
Answer:
No, any magnet has always two poles namely north and south. We cannot make a magnet with only one pole.
Let Us Enhance Our Learning
Question 1.
Fill in the blanks:
(i) Unlike poles of two magnets ………….. each other.
(ii) The materials that are attracted towards a magnet are called …………
(iii) The needle of a magnetic compass rests along the ………… direction.
(iv) A magnet always has ………… poles.
Answer:
(i) attract
(ii) magnetic, materials
(iii) North-South
(iv) two.
Question 2.
State two whether the following statements are True (T) or False (F) :
(i) A magnet can be broken into pieces to obtain a single pole.
(ii) Similar poles of a magnet repel each other.
(iii) Iron filings mostly stick in the middle of a bar magnet when it is brought near them.
(iv) A freely suspended bar magnet always aligns with the north-south direction.
Answer:
(i) False
(ii) True
(iii) False
(iv) True.
Question 3.
Column I shows different positions in which one pole of a magnet is placed near that of the other. Column II indicates the resulting interaction between them for different situations: Fill in the blanks:
Answer:
| Column I | Column II |
| N-N | Repulsion |
| N-S | Attraction |
| S-N | Attraction |
| S-S | Repulsion |
Question 4.
Athrav performed an experiment in which he took a bar magnet and rolled it over a heap of steel U-clips (Fig. 15). According to you, which of the options given in table is likely to be his observation ?
Table : Number of pins attracted by the magnet at its various positions.
| Position A | Position B | Position C | |
| (i) | 10 | 2 | 10 |
| (ii) | 10 | 10 | 2 |
| (iii) | 2 | 10 | 10 |
| (iv) | 10 | 10 | 10 |
Answer:
From the figure, it is clear that the ends of the magnet have more iron fillings attached to it. This is because the strength of a magnet lies more at the ends of the magnet. Hence option (i) is correct.
Question 5.
Reshma bought three identical metal bars from the market. Out o these bars, two were magnets and one just a piece of iron. How will she identify which two amongst the three could be magnets (without using any other material) ?
Answer:
Take all the metal bars and suspend them separately. Bring one end of a bar magnet close to both the ends of the suspended bars. If it shows attraction at both the ends, then it is an iron bar. If it shows attraction at one end and repulsion at the other end, then they are bar magnets.
Question 6.
You are given a magnet which does not have the poles marked. How can you find its pole with the help of another magnet which has its poles marked ?
Answer:
We take the bar magnet whose poles are marked N and S. We bring the N-pole end of this bar magnet near both the ends of the given bar magnet, turn by turn. The end of given bar magnet which will be repelled by the North pole of this magnet will be its North pole because like poles repel each other.
Question 7.
A bar magnet has no marking to indicate its poles. Mow would you find out near which end its North pole is located without using another magnet ?
Answer:
Take the bar magnet and suspend it freely with the help of a thread. The end that points towards north will be regared as north pole of the magnet. The end that points towards south will be regarded as south pole of the magnet.
Question 8.
If the earth is itself a magnet, can you guess the poles of earth’s magnet by looking at the direction of the magnetic compass ?
Answer:
The north of the compass needle always points towards north. Therefore, by observing the direction of the needle, we can found out the desired direction and can guess the poles of earth’s magnet.
Question 9.
While a mechanic was repairing a gadget using a screw driver, the steel screws kept falling down. Suggest a way to solve the problem of the mechanic on the basis of what you have learnt in this chapter.
Answer:
Have a lining of rubber all around the gadget. Inside this rubber lining, keep a long and thin strip of magnet. The thin strip of magnet attracts the steel scews.
Question 10.
Two rings magnets X and Y are arranged as shown in Fig. 16. It is observed that the magnet X does not move down further. What could be the Fig.16. Two ring possible reason ? magnets. Suggest a way to bring the magnet X in contact with magnet Y, without pushing either of the magnets.
Answer:
Like poles of magnets X and magnet Y are facing each other causing repulsion between the two magnets. This force of repulsion makes the magnet X float above magnet B.
Question 11.
Three magnets are arranged on a table in the form of the shape shown in Fig. 17. What is the polarity, N or S at the ends 1, 2, 3, 4 and 6 of the magnets ? Polarity of end(s) is given for you.
Answer:
Activities:
Activity 1.
Aim: To identify the materials which are attracted by magnet and not attracted by the magnet.
Materials Required : Pencil, eraser, an iron nail, paper clip, brass screw, aluminium foil, brass scew, aluminium foil, combs, sewing needle, piece of paper, copper wire and a magnet.
Procedure:
- Collect a few objects made of different materials and a magnet.
- Hold the magnet in your hand and bring it near the objects one by one.
- Observe which of the objects stick to the magnet.
| Name of the object | Material which the object is made of (plastic / wood / glass / iron / any other) | Attracted by the magnet (Yes / No) |
| 1. Pencil | Wood | No |
| 2. Eraser , | Rubber | No |
| 3. Iron nail | Iron | Yes |
| 4. Paper clip | Iron | Yes ! |
| 5. Brass screw | Brass | No |
| 6. Aluminium foil | Aluminium | No |
| 7. Piece of paper | Paper | No |
| 8. Copper wire | Copper | No |
| 9. Comb | Plastic | No |
| 10. Sewing needle | Iron | Yes |
Result :
- Pencil, eraser, brass screw, aluminium foil, piece of paper, copper wire, comb are not attracted by a magnet.
- Iron nail, paper clip, swing needle are attracted by a magnet
Conclusion : Some of the objects are attracted to the magnet and stick to it, while others were not.
Activity 2.
Aim: To show that magnetic force is maximum at the ends magnet.
Materials Required: Magnet, iron filings, a sheet of paper.
Procedure :
- Spread some iron filings on a sheet of paper.
- Place a bar magnet over them. Tap the paper and observe carefully what happens to the iron filings.
Observations: Maximum iron filings stick near the ends of the bar magnet while a very few iron filings stick at the remaining part of the magnet.
Conclusion : The ends of a magnet where maximum iron filings are attracted, i.e., the magnetic force is maximum, are called poles of the magnet.
The end portions of the magnets are the poles of the magnet. It is not possible to obtain a magnet with a single pole. If a magnet is broken into smaller pieces, North and South poles always exist in pairs even in the smallest piece of the magnet. A single North pole or a South pole cannot exist.
Activity 3.
Aim : To show that a magnet always comes to rest in a fixed direction.
Materials Required : A bar magnet, wooden stand.
Procedure:
- Suspend a bar magnet with a thread tied to the middle of the magnet.
- Now rotate the magnet gently in the horizontal direction and let if come to rest.
- Mark the position corresponding to the ends of the magnet on the ground or on a piece of paper stuck to the ground. Join these two points on the ground with a line. This line indicates the direction along which the magnet comes to rest.
- Now again rotate the magnet by giving a gentle push at its one end and wait till it comes to rest.
Conclusion : A freely suspended magnet comes to rest along the north-south direction because our earth itself behaves like a giant magnet.
Activity 4(a).
Aim: To make an iron needle a magnet.
Materials Required : Iron sewing needle, a permanent bar magnet.
Procedure:
- Place the iron sewing needle on a wooden table. Then keep any one pole of the magnet at one end of the needle. Move the magnet over the needle along its length. When it reaches the other end of the needle, lift it up.
- Bring the same pole of the magnet you started with the same end of the sewing needle from which you began, and repeat the previous step. Repeat this process at least 30-40
- Bring some iron filings near the needle. If the iron filings get attracted to the needle, then that means that the needle has become a magnet.
Conclusion : Any piece of iron or steel can be magnetised by stroking it with a strong magnet.
Activity 4(b).
Aim : To make a compass needle in a bow of water.
Materials Required: An iron needle, a cork piece, a permanent bar magnet, a glass bowl and water.
Procedure :
- Pass the needle through the cork horizontally. Float the cork in a glass bowl filled with water, such that the needle always remains above the level of water.
- When the needle comes to rest, your magnetic compass is ready for use. Note the direction in which either side of the needle points.
- Rotate the cork gently and wait till it stops rotating. Repeat this a few more times.
Observations: The ends of the needle always point in the same direction.
Result : Thus a simple magnetic compass is ready to use.
Modern Magnetic Compass : It consists of a magnetised fish shaped iron piece, kept in a vessel of oil. It was called matsyayantra (or machchh-yantra)
Activity 4.5.
Aim: To show that (i) the opposite poles of two magnets attract each other (ii) similar poles of two magnets repel each other.
Materials Required : Two bar magnets, 5-6 round shaped pencils.
Procedure:
- Take a pair of bar magnets on which North and South poles have been marked. Mark the two bar magnets as A and B.
- Place the larger side of magnet A over 5-6 round shaped pencils.
- Now bring one end of magnet B near the end of magnet A placed on the pencils.
- Next, bring the other end of the magnet B near the same end of magnet A.
Observations:
- N-pole brought near to N -pole repels.
- S-pole brought near to S-pole repels.
Conclusion: If two magnets are brought close together, then like magnetic poles will repel each other and unlike magnetic poles will attract each other.
Precaution : Make sure that the two magnets do not touch each other.
Activity 6.
Aim : To show the behaviour of a compass needle if a magnet is brought closer to it.
Materials Required : A magnetic compass, a bar magnet.
Procedure :
- Take a magnetic compass and a bar magnet.
- Place the magnetic compass over a horizontal surface. Wait for its needle to come to rest.
- Now slowly bring North pole of the bar magnet close to the North pole of the compass needle.
- Observe the compass needle carefully.
- Now repeat the above step with the South pole of the bar
Observation :
- When the North pole of a magnet is brought closer to the North pole of the compass needle, it moves away.
- When the south pole of the magnet is brought closer to the north pole of the compass needle, it moves closer.
Conclusion : Like poles of a magnet repel and unlike poles attract each other.
Activity 7.
Aim : To show the magnetic effect can act through non-magnetic materials.
Materials Required : A bar magnet a magnetic compass, a piece of wood / cardboard / plastic / glass, iron filings.
Procedure:
- Place the magnetic compass over a horizontal surface.
- Slowly bring North pole of the bar magnet close to the North pole of the compass needle.
- Now repeat the above step with the south pole of the magnet.
- Without disturbing the bar magnet and magnetic compass, place a piece of wood between them perpendicular to the needle. Observe the compass needle carefully.
- Repeat the process by replacing the piece of wood by a card-board sheet, thin plastic sheet, a thin glass sheet.
Observation:
| S.No. | Materials placed between the magnet and the compass needle | Observations |
| 1. | Wood | |
| 2. | Card board | |
| 3. | Plastic | |
| 4. | Glass |
Observations: There is no appreciable change in the deflection of the needle when a sheet of any of the above material is placed between the magnet and the compass needle.
Conclusion: The magnetic effect can act through non-magnetic materials.