magnets and electromagnets

bar magnets
1. permanent magnets
2. magnets are made from magnetic material.these are metals that can be magnetised or will be attracted to a magnet.most materials are not magnetic,but iron,cobalt,nickel and steel are.
3. attract and repel
  1. if you bring 2 magnets together 2 things can happen-attract or repel.
magnetic fields
1. magnets create magnetic fields.these cant be seen.they fill the space around a magnet where the magnetic forces work,where they can attract or repel
2. although we cannot see them,we can detect them with iron filings.the tiny pieces of iron line up in a magnetic field.
electromagnets
1. when an electric current flows in a wire it creates a magnetic field around the wire.by winding the wire into a coil we can srengthen the magnetic field.electrommagnets are made from coils like this.we can strengthen the electromagnet wrapping the coil around a iron core.-adding more turns to the coil.-increasing the current.
2. magnetic field
  1. the magnetic field of an electromagnet is like a bar magnet one however it can change direction
  2. unlike bar magnets that are permanent magnets,electromagnets can be turned o and off by closing or opening the switch.
electric bells
1. electric bells have an electromagnet.
  1. 1)the current flows through the circuit,the electromagnet makes a magnetic field.
    1. 2)electromagnet attracts the springly metal arm.
      1. 3)the arm hits the gong,which makes a sound.
        4)the circuit is broken.the arm is out of position.
        5)electromagnet turned off and the springly metal arm moves back.
        6) the circuit is complete again.

Next up

magnets and electromagnets

Description

Resource summary

Media attachments

Similar

	Created by gabriel.barcelo over 10 years ago