1 / 12

Electromagnetism ( S8P5 b, c)

Electromagnetism ( S8P5 b, c). Physical Science Candace Black Spring, 2010. Electric Current and Magnetism. Electric current produces a magnetic field. The relationship between electricity and magnetism is called electromagnetism. Can you identify the 3 necessary parts of a circuit?.

nasia
Download Presentation

Electromagnetism ( S8P5 b, c)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electromagnetism(S8P5 b, c) Physical Science Candace Black Spring, 2010

  2. Electric Current and Magnetism • Electric current produces a magnetic field. • The relationship between electricity and magnetism is called electromagnetism Can you identify the 3 necessary parts of a circuit?

  3. Solenoids 3 characteristics of magnetic field produced by current: 1. Can be turned on or off. 2. Direction can be reversed. 3. Strength can be changed. A coil of wire with a current is called a solenoid.

  4. Electromagnets • A solenoid with a ferromagnetic core is called and electromagnet. • Magnetic field is produced by both the current in the wire and the magnetized core. • A strong magnet that can be turned on and off. • Increase strength by: 1. Increasing current 2. Add more loops 3. Place coils closer together 4. Use stronger ferromagnetic material as core.

  5. Uses of Electromagnets • Audiotapes, videotapes, computer hard drives, credit cards… • Doorbell • Fire doors…(be able to explain how these work in our school) • To lift heavy objects such as junk cars, metal containers such as are used in shipping, etc.

  6. Electric Motors A device that uses an electric current to turn an axle. Transforms electrical energy into mechanical energy.

  7. In your notes, write at least 3 things that you can think of that use motors.

  8. Induction of Current • Electric current is induced in a conductor when the conductor moves through a magnetic field. • Generating an electric current from the motion of a conductor through a magnetic field is called electromagnetic induction. • Current that is generated in this way is called induced current.

  9. A current consisting of charges that flow in one direction only is called a direct current or DC. Example: battery operated items; charges flow from positive end through circuit back to negative end. A current that flows back and forth in a circuit is called an alternating current or AC. Example: homes, buildings, schools, Advantage: voltage can be raised or lowered; higher voltages can travel over longer distances (from power plant); then can be lowered for everyday use (in our homes). Induced Currents

  10. Generators • An electric generator is a device that transforms mechanical energy into electrical energy. • A generator uses motion in a magnetic field to produce an electric current. • Electric motors use and electric current in a magnetic field to produce motion. • Generators are used in power plants with turbines acting as the crank. Be able to compare/contrast generators and motors.

  11. Transformers • A transformer is a device that increases or decreases voltage. (voltage is…?) • Consists of 2 separate coils of insulated wire wrapped around an iron core. • Two types of transformers are: 1. step-up transformer —increases voltage. 2. step-down transformer —decreases voltage.

  12. ??????????? What are your questions?

More Related