Magnetism is a force that can attract (pull closer) or repel (push away) objects that have a magnetic material like iron inside them (magnetic objects). Magnets can be affected by electricity, which makes them very useful in machines and computers. Magnets are used to make a tight seal on the doors to refrigerators and freezers, etc. MEANING OF MAGNET A magnet is a substance which can attract iron or steel material to itself. Magnets are made of iron or steel. TYPES OF MAGNETS There are two types of magnets: \t Permanent Magnets Permanent magnets remain magnetized even without the influence of external magnetic field, such as a horseshoe magnet. \t Temporary Magnets Temporary magnets may lose their magnetism when removed from the external magnetic field, such as an iron pin. See also FRICTIONAL FORCES FORCES PROPERTIES OF MAGNETS \tMagnets attract ferromagnetic materials, such as iron, nickel, and cobalt. \tAll magnets have two poles: North Pole and South Pole. There are no magnets containing only one pole. \tLike poles of two magnets repel each other; opposite poles of two magnets attract each other. \tThe magnetic force of a magnet is stronger at its poles than in the middle. \tThe stronger the magnets and the closer two magnets are to each other, the greater the magnetic force exerted on each other. \tWhen a bar magnet is suspended by a thread freely in horizontal position, its north pole will move towards the North Pole of the earth and its south pole will move towards the South Pole of the earth. This is because the earth is a giant magnet, and its geographical north pole is its magnetic south pole, and vice versa. USES OF MAGNETS Magnets have their lot of applications in the daily life. The major 10 uses of the magnets are as follows: \tThey are also used to sort out the magnetic and non-magnetic substances from the scrap. \tThey are used in TV screens, computer screens, telephones and in tape recorders. \tThey are used by the candy or cold drink vendors to separate the metallic cap from the lots. \tThey are used in cranes. \tThey are also used in the speakers which can convert the electrical energy into sound energy. \tThey are used in the electrical bells. \tThey are used in the refrigerators to keep the door close. \tThe most important use of the magnet is the magnetic compass which is used to find the geographical directions. \tThey are used to construct the electrical motors and the generators which convert the electrical energy into mechanical energy and vice versa. \tThey are used in the Maglev trains. In the Maglev trains, the super conducting magnets are used on the tracks on which the train floats. These types of the trains are working on the repulsion force of the magnets. MAKING A TEMPORARY MAGNETS \tRub the magnet against the paperclip. \tMove it in the same direction, rather than back and forth. \tUse the same quick motion you’d use to light a match. \tContinue rubbing the paperclip with the magnet 50 times as quickly as you can. See also PULLEYS LEVERS Strategies & Activities Step: Teacher revises the previous topic Step 2: Teacher introduces the new topic. Step3: Teacher endeavors to explain all the points to the pupils thoroughly. Step 4: Teacher welcomes pupils’ questions. Step 5: Teacher evaluates the pupils. Assessment & Evaluation \tState two of properties of a magnet; \tName three common appliances that use magnets; \tGroup materials into magnetic and non-magnetic materials; \tMake temporary magnets.