The document discusses magnetism and electricity concepts including: - Iron, nickel, and cobalt have the greatest magnetic permeability. - Permanent magnet examples include ceramic bars, fridge magnets, and neodymium discs. - Temporary magnets include induced paper clips and electromagnets. - Earth's magnetic field is generated by a dynamo effect in its solid iron inner core. - Moving a magnet near a wire or changing the magnetic field around a wire induces electric current in the wire.

1. Electronic Technology

2. Magnetism Review What 3 common metals have the greatest magnetic permeability? Name 3 examples of permanent magnets. (shape & material) Name 2 types of temporary magnets. Describe the domains of a magnet. What is the only naturally-occurring magnet found in the Earth's crust? What type of "magnet" is responsible for Earth's magnetic field? Describe Earth's core. iron, nickel & cobalt ceramic bar, flexible & flat fridge magnet, neodymium disc induced paper clip, electromagnet aligned (same dir.) lodestone "dynamo" electromagnet solid iron inner core, surrounded by swirling liquid iron

3. Magnetism Review What word is used to describe Earth's magnetic pole's angle of variation from the geographic poles? Describe the shape and polarity of Earth's magnetosphere. True or False: The strength and location of Earth's magnetic poles constantly change; there's even evidence they've been reversed in the past. Why is the magnetosphere important? What do magnetic storms do? Name 5 devices that use electromagnets . declination geographic north is magnetic south, sun-side is "squashed" true solar wind protection heat/distort atmosphere MRI, hairdryer, car door locks, speaker, maglev train, crane, electric toothbrush, toys, etc.

4. Magnetism Review Every wire carrying electricity has a weak around it. What does the "right-hand rule" show us? How does looping a wire carrying electricity affect the magnetic field around it? What is a coil of current-carrying wire called? What is created by running electric current around a magnetic material? How does reversing the flow of electrons in a current affect the magnetic field? What could you adjust to make a stronger electromagnet? magnetic field direction of current & flux strengthens it solenoid electromagnet reverses poles more current, more/neater coils, better core material, lower temperature

5. Electric Motors An electric motor converts electricity into mechanical motion. Most electric motors are rotary, producing rotational movement (spin, like a fan or turn of a wheel). Stator: the stationary part usually a permanent magnet surrounds the rotor Rotor : the rotating part usually on the inside contains an electromagnet attached to a frame called the armature

6. Creating Motion from Electricity Permanent magnets attract opposite poles of the electromagnet inside, causing it to rotate Turn the electromagnet off momentarily & momentum will keep it turning Then switch the poles of the electromagnet and the stationary magnets pull again, continuing the motion Electromagnet (coils not pictured) N S

7. Motion from Electricity N S N S 3. Reversed poles of electromagnet, continue motion 2. Momentum keeps it turning when switched off 1. Stator magnets attract opposite poles of the electromagnet N S

8. Rotor Assembly Armature (inner rotating part) battery supplies current two brushes (connectors) commutator gaps stop current flow rotation switches poles solenoid (many coils) solid iron core (not pictured) electro-magnet N S split ring commutator brush

9. The Simple DC Motor The force applied to the armature by the stationary magnetic field which causes it to rotate is called torque .

11. Multiple-Electromagnet Motors Most motors have more than one magnet in the armature to assure smooth rotation.

12. Pioneering scientists wondered... If electrical currents can produce a magnetic field, can magnetic fields also produce an electrical current? What do you think? If moving electrons produce a "push" (magnetic field) then that same "push" applied to a wire should cause electrons to move!

13. How is this diagram different than a motor? A hand crank replaces the battery.

14. Creating Electricity from Magnets PhET Simulation Pickup Coil tab Dots moving in the wire represent electric current the faster they travel, the greater the current Reading the Field Meter B (top measurement) gives the overall field strength. G stands for Gauss, the SI unit of magnetic field strength Bx & By give coordinates to graph the flux lines Ө gives the angle (in degrees) of the magnetic lines of force Yellow lines around bulb show electricity is generated longer lines indicate more current

15. Electromagnetic Induction A changing magnetic field causes current to flow in a conductor Mechanical energy (KE - the energy of motion) is converted into electricity Current flows ONLY when the magnetic field changes magnet moves permanent magnet poles are reversed electromagnet

16. Electric Generators A generator is a device which produces current by electromagnetic induction. magnetic forces push electrons through a wire opposite process of a motor requires external energy source

17. Hydroelectric Generator Nuclear Power Generator Human-Power Generator Wind Turbine Generator Steam Turbine Generator