Magnets

• Rapel is when two magnets dont stick together
• Attract is when two magnets stick together
• Magnets are non-contact force of attraction to magnetic metals
• only iron (and steel), cobalt, and nickel are the only magnetic metals
• An induced magnet only becomes a magnet when it is placed in magnetic field
• The earth has a magnetic field
• Magnets have two poles
• Solenoid is a wire coiled around an iron bar
• Electromagnet is a non-contact force from a magnet to a magnetic metal (iron , nickel, cobalt)
• the difference between electromagnets and permanent magnets is that electromagnets can be turned on and off and they can be stronger but permanent magnets cannot be turned on and off
• to make an electro magnet you wrap a wire around a iron bar and connect it to a battery
• to make an electro magnet stronger we need more coils (wrapped wire around an iron core) or increase the current