magnetism & electricity production. what is magnetism? force of attraction or repulsion due to...
TRANSCRIPT
- Slide 1
- Magnetism & Electricity Production
- Slide 2
- What is magnetism? Force of attraction or repulsion due to electron arrangement Magnetic forces are the strongest at the poles Magnets have two poles: North and South
- Slide 3
- Magnetic poles and fields Magnets always have two poles If a magnet is cut it will still have two poles Like magnetic poles repel Unlike magnetic poles attract A magnetic field is the area in which magnetic forces act
- Slide 4
- Magnetic materials Natural magnets have naturally occurring magnetic properties ex: LODESTONE (magnetite)
- Slide 5
- Temporary magnets Easy to magnetize Lose their magnetism quickly Ex: Soft iron
- Slide 6
- Permanent magnets Hard to magnetize Stay magnetized longer than temporary magnets Ex: alnico (cobalt, nickel, aluminum)
- Slide 7
- Earths magnetic properties Gilbert was a scientist that showed that the Earth behaves as a magnet The Earths magnetic field is strongest at the poles Earths magnetic field is called the magnetosphere
- Slide 8
- Compasses Compasses are used to determine direction Compass needles are magnetized and respond to the magnetic field of the Earth Compasses point to the Magnetic Poles Of The Earth
- Slide 9
- Other sources of magnetism Magnetic fields of the Earth and other planets are related to their cores The sun is a source of a magnetic field
- Slide 10
- Magnetic variation Magnetic poles of the Earth are different from the geographic poles of the Earth Magnetic poles shift positions; geographic poles are constant
- Slide 11
- Magnetic Induction Process by which materials can be magnetized
- Slide 12
- What affects magnetic properties? Spinning electrons cause some metals to have magnetic properties Magnetic domains are groups of arranged magnetic fields Dropping, hammering or heating a magnet will cause a magnet to lose magnetic properties
- Slide 13
- Linking Magnetism & Electricity
- Slide 14
- Electromagnetism Discovered by Oersted (scientist) Relationship between electricity and magnetism
- Slide 15
- Electromagnets Temporary magnets Magnetism can be turned on and off Made by wrapping wire around a piece of iron and sending a current through the wire Magnetic field is in the same direction as the electric current
- Slide 16
- Electromagnets
- Slide 17
- Increasing the strength of electromagnets Increasing the voltage or current Increasing the number of loops of wire
- Slide 18
- Electric motors vs. generators Electric motors convert electricity to mechanical energy in order to do work Generators convert mechanical energy to electrical energy
- Slide 19
- Generators
- Slide 20
- Transformers Used to increase or decrease voltage Made of primary and secondary coils
- Slide 21
- Transformers Two types of transformers: Step-up (increase voltage) Step-down(decrease voltage)
- Slide 22
- Questions What two forces are involved in magnetism? Attraction & Repulsion Which subatomic particle accounts for magnetism? electrons
- Slide 23
- Questions Explain the interaction between magnetic poles when they are close together. Like magnetic poles repel Unlike magnetic poles attract
- Slide 24
- Questions How is a temporary magnet different from a permanent magnet? Temporary magnets are easy to magnetize & lose their magnetism quickly Give an example of a natural magnet. Lodestone
- Slide 25
- Questions Which scientist described the Earths magnetic properties? Gilbert
- Slide 26
- Questions Name the devices used to indicate geographic direction based on the Earths magnetic field. Compasses
- Slide 27
- Questions What is the name of the Earths magnetic field? Magnetosphere Where is the Earths magnetic field the strongest? At the poles
- Slide 28
- Questions Explain magnetic variation. Magnetic poles of the Earth are different from the geographic poles of the Earth Magnetic poles shift positions; geographic poles are constant
- Slide 29
- Questions What is electromagnetism? Relationship between electricity and magnetism Who discovered electromagnetism? Oersted
- Slide 30
- Questions Name two ways to increase the strength of an electromagnet. Increasing the voltage or current Increasing the number of loops of wire
- Slide 31
- Questions What type of magnet is an electromagnet? Temporary magnets Magnetism can be turned on and off Made by wrapping wire around a piece of iron and sending a current through the wire Magnetic field is in the same direction as the electric current
- Slide 32
- Questions How is a generator different from an electric motor? Electric motors convert electricity to mechanical energy in order to do work Generators convert mechanical energy to electrical energy
- Slide 33
- Questions Name two types of transformers. How is a step-up transformer different from a step down transformer? Step-up (increase voltage) Step-down(decrease voltage)
- Slide 34
- Questions What are the two parts of a transformer? A coil Windings + An AC Source