MAGNETIZATION

1. MAGNETIZATION What it is? How is it applied in everyday life!

2. What is magnetization? • Magnetization can simply be defined as a process that makes a substance magnetic (temporary or permanent). • It can also be considered the physical property of being magnetic.

3. What are magnets? • A magnet is an object made of certain materials which create a magnetic field.  • Every magnet has at least one north pole and one south pole. • By convention, we say that the magnetic field lines leave the North end of a magnet and enter the South end of a magnet. 

4. What are magnets?

5. What is a magnetic field? • A magnetic field is an invisible field which exerts magnetic force on substances which are sensitive to magnetism.

6. Magnetic Fields • Magnetic fields used have a wide range of uses, namely: - used in navigation, ships can orient themselves with the assistance of the Earth's magnetic field - magnetic fields can be used to gather information about a location or object - medicine has a use for magnetic fields, in things like diagnostic machines such as Magnetic Resonance Imaging (MRI) equipment.

7. Magnetic Fields

8. What is a magnetic force? • A magnetic force is when a magnetized piece of either iron, steel, nickel or cobalt comes close to either an other magnet or a demagnetized piece of iron, steel, nickel or cobalt. This is measured in Newton.

9. Magnetic Flux • Magnetic Flux is a measure of quantity of magnetism, taking into account the strength and the extent of a magnetic field.

10. Building a simple circuit • Material required: - Battery - insulated copper wire - light bulb

11. Building a simple circuit Batteries- • Batteries are assembled from cells, connected in series, to increase the voltage available. • In a cell, chemical energy is converted into electrical energy.  • Cells may be either PRIMARY or SECONDARY types. • A primary cell is discarded when its chemical energy is exhausted. • A secondary cell can be recharged

12. Building a simple circuit- Battery

13. Building a simple circuit What is an electric current? • An electric current is a flow of microscopic particles called ELECTRONS flowing through wires and electronic components. What is an electron? - The electron is a subatomic particle that carries a negative electric charge. It has no known substructure and is believed to be a point particle.

14. Building a simple circuit • A basic law of the universe is that like charges repel and unlike attract. Two negatives will repel each other. A negative and a positive will attract each other. • An electron has a negative charge.  • The negative (-ve) terminal of a battery will push negative electrons along a wire. • The positive (+ve) terminal of a battery will attract negative electrons along a wire.

15. Building a simple circuit • Electric current will therefore flow from the negative (-ve) terminal of a battery, through the lamp, to the positive terminal.

16. Building a simple circuit

17. Simple definitions • Circuit- a closed loop of conductors through which charges can flow • Conductor- a substance through which electrical charges can easily flow • Current- a flow of electrical charges • Generator- a device for producing electrical current by moving a coil of wire in a magnetic field • Insulator- a material through which electric charges cannot move

18. Simple definitions • Ion- an atom that has gained or lost one or more electrons and is thus a charged particle • Switch- a device that closes or opens a circuit, thereby allowing or preventing current flow • Voltage- the pressure behind the flow of electrons in a circuit

19. Construction of a simple generator • A simple generator can be constructed from everyday materials that can be found around the house. • This is a very fun and exciting way to understand how the generator works and the significance of the different parts used in construction.

20. Construction of a simple generator • Parts list: • 4 - 1x2x5cm ceramicmagnet • 1 - #30 Magnet wire 200ft • 1 - Miniature Lamp, 1.5V 25mA • 1 - Cardboard strip, 8cm x 30.4cm • 1 - Large nail, 8cm long or more • Misc. - Knife or sandpaper to strip the wires • Misc. - tape to hold wire down

21. Construction of a simple generator • First make the hollow-ended box. Score the cardboard strip like so:

22. Construction of a simple generator • Fold it like this and tape securely:

23. Construction of a simple generator • Use the nail to poke a hole perfectly straight through the center of the box, going through both sides and all three layer of cardboard. Then pull the nail out and use it to widen all the holes slightly, so when you put the nail back through, it will be a bit loose and able to spin.

24. Construction of a simple generator • At this point you should clamp your four magnets around the nail and give it a spin. This makes sure the box is large enough. The nail and magnets should spin freely. The corners of the magnets should NOT bump the inside of the box as they spin. • If the box is a bit too small, start over and make it a little bigger. Either that, or try a thinner nail. (Also, be sure to use the right magnets. Small ones won't work.)

25. Construction of a simple generator • Pick the spool of number-30 magnet wire from the kit of spools. This is the thinnest. Tape one end of the number-30 magnet wire to the side of the box, then wind all of the wire onto the box as shown. It's OK to cover up the nail hole. Pull the taped end of the wire out, then tape down both of the wires so the coil doesn't unwind. You should have about 10cm of wire left sticking out.

26. Construction of a simple generator

27. Construction of a simple generator • Use sandpaper or the edge of a knife to scrape the thin plastic coating off 2cm of the wire ends. Remove every bit of red coating so the wire ends are coppery.

28. Construction of a simple generator • Spread the wire away from the nail hole and tape it in place. • Stick the nail back through the holes and make sure it can spin. • Take your four magnets; stick them face to face in two pairs. Then stick the two pairs inside the box and on either side of the nail so they grab the nail. • Push them around until they are some-what balanced and even, then spin the nail and see if they turn freely. • If you wish, you can stick 2cm squares of cardboard between the magnets to straighten them, and tape the magnets so they don't move around on the nail.

29. Construction of a simple generator

30. Construction of a simple generator • Twist the scraped end of each generator wire securely around the silver tip of each wire from the small light bulb. • (If necessary, use a knife to strip more plastic from the ends of the light bulb wires.) • One generator wire goes to one light bulb wire, the other generator wire goes to the other light bulb wire, and the two twisted wire connections should not touch together. In the twisted wires, metal must touch metal with no plastic in between.

31. Construction of a simple generator

32. Testing of Simple Generator • Spin the magnet REALLY fast and the bulb will light dimly. • If it doesn't work, try spinning it in a dark room so you don't miss the dim glow. • If needed, adjust the position of the magnets so they don't hit or scrape the cardboard. This thing has to spin *fast*, and if the magnets whack the cardboard and slow down, you won't see any light. • Spin it faster than eight revs per second.

33. Testing of Simple Generator

34. Conclusion • Physics plays an important role in our everyday lives. • Hope you had fun. • Remember always practice safety!!!!