Magnetism ICSE Class-6th Concise Selina Physics Solutions
Magnetism ICSE Class-6th Concise Selina Physics Solutions Chapter-6. We Provide Step by Step Answer of Objective, True False , Fill in the blanks, Match the following , Short / Long Answer Type , Numerical s of Exercise-6 Magnetism . Visit official Website CISCE for detail information about ICSE Board Class-6.
Magnetism ICSE Class-6th Concise Selina Physics Solutions Chapter-6
A. Objective Questions
1. Write true or false for each statement.
(a) Artificial magnets are weaker than the natural magnets.
Artificial magnets are stronger than the natural magnets.
(b) Poles of a magnet cannot be separated.
(c) A magnet can attract only a magnetic substance.
(d) A magnet has no effect when it is heated to a high temperature.
Magnet get demagnetized when it is heated to a very high temperature.
(e) Permanent magnets get easily demagnetized.
Permanent magnets can not be demagnetized.
(f) Magnetic poles occur in pairs.
(g) Single touch method is better than the electrical method for making a magnet.
Electrical method is better than single touch method.
(h) Magnetic keeper is a wooden piece.
Magnetic keepers are the pieces of soft iron.
(i) Copper cannot be magnetized.
2. Fill in the blanks “Magnetism ICSE Class-6th”
(a) Temporary magnets are usually made up of soft iron.
(b) Rough handling destroys the magnetic properties of a magnet.
(c) Like poles repel each other.
(d) A freely suspended magnet points in the north-south direction.
(e) In a magnet, ends have the maximum attractive property.
(f) A magnet has two poles.
3. Match the following
4. Select the correct answer (Magnetism ICSE Class-6th)
(a) If we suspend a magnet freely, it will settle in .
- east-west direction
- north-south direction
- north-east direction
- east-south direction
(b) Making a magnetic substance a magnet by bringing it closer to another magnet without touching it, is
- magnetic induction method
- single touch method
- double touch method
- electrical method
magnetic induction method
(c) An example of natural magnet is
- none of above
(d) The artificial magnet used to detect direction in the laboratory is
- U-shaped magnet
- horse shoe magnet
- magnetic compass
B. Short/Long Answer Questions (Magnetism ICSE Class-6th)
What is a magnet ?
The substances which have the property of attracting iron, are called magnets.
What are magnetic and non-magnetic substances ? Give two examples of each.
Magnetic substances: The substances that get attracted by a magnet are called magnetic substances. Iron, steel, cobalt and nickel are magnetic substance
Non-magnetic substances : The substances that do not get attracted by a magnet are called non-magnetic substances, e.g., wood, plastic, copper, paper, aluminium, rubber, stone.
What are natural and artificial -magnets ?
Natural magnets: Natural magnets are those which are found in nature e.g. load stone.
Artificial magnets: Man made magnets are called artificial magnets, e.g. electromagnet.
How is an artificial magnet prepared from a natural magnet ?
Pieces of iron or other materials are made magnets by rubbing them with natural magnets (or by passing direct current through a wire wound around them). This is how artificial magnets are made.
State two ways of magnetizing an iron piece.
The two ways of magnetizing an iron piece are:
Magnetic induction method.
Take a long iron nail and test it for magnetic properties by bringing near the magnetic substances. You will see nail does not attract the magnetic substances. Now bring near a pole of a bar magnet to the head of the nail. Now bring the iron paper clips near the pointed end of the nail, you will observe that the iron paper clips now get attracted towards the nail. This is because iron nail has become magnet. Now take the bar magnet away form the iron nail, paper clips fall off. This magnetism is temporary.
Single touch method:
Take a demagnetised piece of iron. Place it on a table surface. Take a magnet and select its one pole. Now mb it with the selected pole on the iron in one direction for several times. After sometime, the iron piece turns into a magnet
How can magnetic properties of a magnet be destroyed ?
- By hammering the magnet repeatedly.
- and By rough handling
- By heating.
Why docs a freely suspended magnet always rest in north- south direction ?
A freely suspended magnet always rest in north-south direction because the north-pole of the magnet lies in the geographic north direction and the south pole of the magnet lies in the geographic south direction. So it aligns itself in N-S direction. As unlike poles attract and like poles repel.
Draw diagrams of the artificial magnets offour different shapes.
Why are the artificial magnets preferred over the natural magnets ?
Artificial magnets are preferred over natural magnets because natural magnets are weak and often irregular in shape, they can readily be magnetised and demagnetised by turning the current on or off in the coil.
Describe an experiment to show that the maximum attractive property is at the poles of a magnet.
Take a bar magnet and place a steel pin at some distance. We observe that nothing happens. Now, bring the steel pin near the pole of the bar magnet. We notice that pin sticks to the magnet. This experiment shows that maximum magnetic force acts at the poles of the magnet.
State four important properties of a bar magnet.
- Attractive property: A magnet can attract small pieces of iron filing or other ferromagnetic materials.
- Directive property: If a magnet is suspended horizontally by a thin thread (say silk thread), it rests always pointing north- south direction of earth.
- Like poles always repel each other and unlike poles attract each other.
- Poles always exist in pairs : Single pole can never exist.
Explain the attractive property of a magnet with the help of an experiment.
Take iron filling on a piece of paper. Bring a bar magnet near it. Iron filling will cling to it. It shows the attractive property of magnet.
Describe the method by which an iron bar can be made a magnet.
Single touch method : Place the iron bar (or the needle) AB on a table. Take a bar magnet NS and place it almost vertical with its north pole (N) on the end A of the bar.
Move the magnet along tire iron bar till the other end B is reached.
Lift the magnet at the end B and again place it on the first end A Again stroke the bar. Repeat the process about 20 times. Then turn the iron bar AB upside down. Again stroke it with the mag¬net about 20 times. The bar now becomes a magnet.
How are the magnets kept safely ? What is the role of keepers in storing the magnets ?
When magnets are not in use they should be kept and stored in magnetic keepers. The magnetic keeper are the pieces of soft iron. A magnetic keeper has a card board with one or two iron soft pieces. Two magnets are placed in such a way that their opposite poles are close to each other and then a soft iron keeper is attached with it.
Define the term magnetic field of a magnet. How will you recognise it experimentally ?
The space around a magnet in which if a magnetic substance such as small pieces of iron, are placed, they get attracted to-wards the magnet, is called the magnetic field.
Recognition of the magnetic field around a magnet: If a magnet is placed below a sheet of stiff paper and some iron filings are spread on it, then on tapping the sheet gently, the iron filings are found to arrange themselves in a definite pattern .
How will you make an iron bar electromagnet ? Draw a diagram showing the polarities of the electromagnet.
Take the given iron bar AB. Wound several turns of insulated copper wire over the bar. Connect the ends of the wire to a battery through a switch. Press the switch to pass current. After some time, the bar AB becomes a magnet.