Electromagnets.ppt
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This document discusses electromagnets and the factors that affect their magnetic fields. It explains that an electromagnet's magnetic field is produced by electric current flowing through a coil. The key factors that strengthen the magnetic field are: 1. Using a ferromagnetic core material like iron inside the coil 2. Increasing the number of loops or turns of wire in the coil 3. Increasing the electric current running through the coil The document provides examples comparing different electromagnets based on variations in these factors, and explains that the magnetic force is calculated as the product of the current and number of turns.
Electromagnets.ppt
- 1. ELECTROMAGNETS Objectives: 2.4 Demonstrate the effect of a core on the behavior of an electromagnet 2.5 Explain the properties of magnetized matter using the simplified atomic model. 2.6 Factors that affect the magnetic field of an electromagnet 2.7 Determine the mathematical relationship that affects the magnetic force of an electromagnet.
- 2. Electromagnet An electromagnet is a type of magnet in which the magnetic field is produced by electric current. A metal core cylinder is inserted in a solenoid. A solenoid is a coil of “live” wire.
- 3. Factors that affect the Magnetic field of an Electromagnet 1. The core material 2. The current intensity 3. Number of loops Important
- 4. Core Material A Core is the object that is inserted into the solenoid, creating an electromagnet Ferromagnetic cores strengthen the magnetic field Iron, steel, nickel & cobalt Iron is a VERY GOOD core material Wood, plastic, and aluminum are not good materials for a core.
- 5. Which has a stronger magnetic field? A B Iron Wood 1 - Number of loops is the same 2 – Intensity is the same 3 – But the core is different I = 5 amps I = 5 amps Result: (A) Iron is better because it is a ferromagnetic core
- 6. Number of Loops More loops, more strength. Few loops Many loops
- 7. Which has a Stronger Magnetic Field A B Iron Iron Intensity is the same Core is the same # of loops are different I = 2 amps I = 2 amps 3 loops 5 loops Result: B is stronger: more magnetic loops = a stronger magnetic field
- 8. Current Intensity More amps, more strength. I = 5 amps I = 10 amps
- 9. Which has a Stronger Magnetic Field A B Iron Iron # of loops is the same Core is the same Intensity is different I = 2 amps I = 10 amps 5 loops 5 loops Result: B is stronger because current intensity is greater
- 10. Which has a Stronger Magnetic Field A B Nickel Nickel When loops & the current intensity are different, but cores are the same, use the following equation: F = IN F is force/strength I is the current intensity N is the number of loops I = 5 amps I = 2 amps 3 loops 5 loops
- 11. Which has a Stronger Magnetic Field A B Nickel Nickel I = 5 amps I = 2 amps 3 loops 5 loops Strength of field = current intensity x (# of turns) F = I N A 15 = 5 amps x 3 turns B 10 = 2 amps x 5 turns A therefore has a stronger magnetic field
- 12. Which Electromagnet has the Strongest Magnetic Field Current = 10A Turns = 6 Current = 7A Turns = 10 60 = 10A x 6 turns 70 = 7A x 10 turns Strongest
- 13. Engine Starter Motor A car engine is started with an electric motor. This is based on the St. Louis motor.
- 14. ElectroMagnetic Induction ElectroMagnetic Induction consists in generating an electric current in a conductor by moving a magnetic field around that conductor.
- 15. Factors affecting magnetic field: Core material, Iron is always the best core material Number of turns More loops stronger field * Current Intensity More amps stronger field * * Riley Gagnon Inc.
- 16. Activities P. 174, Q. 26 Student Study Guide Module II – 13 # 1 - 5 Module II - 14 Module II –15 Sec. 2.8 Worksheet # 7
- 17. Origins of Magnetism of Matter Scientists believe that magnetism comes from spinning electrons around the nucleus of the atom. When atoms clump together they form a domain. Enrichment
- 18. Similar electron spins produce a strong domain, where as opposite electron spins cancel one another out and produce a weak domain. If enough domains align in the same direction, this will create a magnetic field. Origins of Magnetism of Matter Enrichment
- 19. How to Magnetize an Object Bring the ferromagnetic substance in contact with another magnet. Bang the ferromagnetic substance (example: striking a nail repeatedly). Heat up the substance and cause the domains to align. Run electric current through the ferromagnetic substance. Please note that all of these methods can also de-magnetize a magnet. Enrichment
- 20. References Student Study Guide Physical Science 416 – MEQ Science Quest, Grenier, Daigle & Rheaune, 1998 Editions Cheneliere Animation Factory Google Images
- 21. Alternative Educational Experiences through e-Learning