YADNYA e-Learning
Science Studies - 6th Standard
15. Fun with Magnets
Question And Answer
1. How will you do this ?
(a) Determine whether a material is magnetic or non magnetic.
Ans: If a material sticks to a magnet then it is a magnetic material otherwise it is a non-magnetic material.
(b) Explain that a magnet has a certain magnetic field.
Ans: A magnet has a certain magnetic field which can be
demonstrated using the below activity. Take a cardboard and sprinkle some iron filings on it. Notice the position of the iron filings as a whole. Now take a bar magnet and slowly bring it below the cardboard. You will observe that the iron filings tend to attract towards the magnet and align themselves as shown. It represents that the magnet exerts a force around its body with a stronger force near the two poles. This regular pattern of the iron filings on the board represents the lines of magnetic field. Thus a
magnet has a certain magnetic field which can be represented by curved lines around a magnet.
(c) Find the north pole of a magnet.
Ans: Tie a thread to the centre of a magnet and hang it from a stand as shown. Wait till the magnet settles itself.
2. Which magnet will you use ?
(a) Iron is to be separated from trash.
Ans: Electromagnet can be used to separate iron from trash.
(b) You are lost in a forest.
Ans: Bar magnet or loadstone can be used to find the direction in the forest. This is because a bar magnet when suspended freely always rests in north-south direction.
(c) A window shutter opens and shuts continuously in the
wind.
Ans: Permanent magnet can be used to stop the continuous shuttering of the window in the wind.
3. Fill in the blanks with the appropriate word.
(a) If a bar magnet is hung by a thread tied at its centre, its north pole becomes steady in the direction of the north Pole of the earth.
(South, north, east, west)
(b) If a bar magnet is cut into equal pieces by cutting it at right
angles to its axis at two places, 3 bar magnets are formed, and
a total of 6 poles are formed.
(6,3,2)
(c) There is repulsion between the like poles of a magnet, and
attraction between its opposite poles.
(opposite, like.)
(d) When magnetic material is taken close to a magnet, the
material acquires induced magnetism.
(permanent magnetism, induced magnetism)
(e) If a magnet attracts a piece of metal, that piece must be made of magnetic material or iron.
(any other metal but iron, magnetic material or iron, non magnetic material)
(f) A magnet remains steady in a north-south direction.
(east-west, north-south)
4. Write the answers in your words.
(a) How is an electromagnet made ?
Ans: When an iron object is wounded with copper wire and current is passed through the wire, the magnetism is produced in the object. This is how temporarily electromagnetism is produced.
(b) Write the properties of a magnet.
Ans: Properties of a magnet are as fallows-
1) Magnet always settles in north south direction.
2) Unlike poles of magnet attach each other while like poles repel each other.
3) The magnetic force is concentrated at the two ends or poles of a magnet.
4) A magnetic material acquires magnetism when placed near a magnet. This magnetism is called induced magnetism.
(c) What are the practical uses of a magnet ?
Ans: The uses of a magnet:
1) Magnets are used in big cranes to remove large metal
pieces.
2) Magnetic needle is used in compass to find direction.
3) They are used in generators.
4) Magnetic materials are also used to store data in hard
disk of a computer, an audio or video tape etc.
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