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C. Short Answer Questions., 1., , , , The substances that are attracted by the magnets are called magnetic, substances. Eg. — Iron, steel, nickel and cobalt are magnetic substances., The substances that are not attracted by the magnets are called nonmagnetic substances. Wood, stone, leather, plastic, aluminium and, copper are non-magnetic substances., , , , , , , , , , S.No. Natural magnets | Artificial magnets, (i) | These are formed in nature. These are prepared by, humans., (ii) | They generally have low They generally have more, magnetic power. magnetic power than natural, magnets., , , , , , A freely suspended magnet always rests pointing in the north-south, direction. This property of a magnet is called directive property. The, end of a magnet that points towards north is called north pole of the, magnet, the other end that points towards the south is called the south, pole of the magnet., , We take a magnet and suspend it with the help of a thread. Now, bring, one end of a metallic bar near one pole of the suspended magnet at, a time. If one end of the metallic bar is attracted and the other end is, repelled, the metallic bar is a magnet. If both the ends of the metallic, bar are attracted, it is not a magnet., , (a) Attractive property of magnet helped Rashmi to find the needle., (b) Rashmi is caring, helpful and obedient., , , , D. Long Answer Questions., , 1., , To make a magnetic compass, , Things needed: A sewing needle, a bar magnet, a cork, acup anda rubber, Method: We can magnetise a sewing needle using a bar magnet. Pass, the magnetised needle through a small piece of cork or rubber. Place, this cork containing the magnetised needle in a cup containing water., Make sure that the needle does not touch water. When the needle, comes to rest, it points to the north-south direction. Rotate the cork, with the needle inserted in it in different directions., , Observation: You observe that the needle always points in the northsouth direction, when the cork stops rotating. The magnetic compass is, ready for use.