Magnetic forces

• A magnet : something that produces a magnetic field
• What are the three naturally occurring magnetic materials?

  Iron, nickel, and cobalt
• Plotting a magnetic field practical:

  1. Place your magnet in the middle of a sheet of white paper
  2. Take some plotting compasses and place them around the magnet, keeping the same distance from the magnet
  3. Draw an arrow in the direction the compasses are pointing
  4. Move them around the magnet and draw the field they are pointing to
  5. Connect the dots with smooth lines to form a magnetic field
• What does this image show?

  Magnetic North and Geographic North are not the same as a magnet’s north pole is attracted to magnetic south

  
• A magnetic object: something that will feel a force of attraction in a magnetic field
• Will a magnetic object be attracted to both ends of a bar magnet - Yes or No?

  Yes
• Will a magnet be attracted to both sides of a bar magnet - Yes or No?


  No
• Why can we induce magnetic objects to become magnetic?

  Magnetic objects contain magnetic domains that usually point in different directions so they cancel each other out, but a magnet can make them all line up and act in one direction so they become a magnet
• Inducing a magnet practical:

  1. Hold a pin and stroke it with the bar magnet in the same direction every time
  2. Carefully pour some water into a dish and place the cork on the water
  3. Observe what happens when you place the pin gently on the cork
• What is the polarity of the end of the imaginary bar magnet inside the earth that is nearest the geographic south pole?

  North
• Explain why the north pole of a compass is often called the north seeking pole

  As opposite poles of a magnet attract and similar poles repel, in order for the compass to show geographic north, the south pole of the magnet must be attracted to the north meaning the north pole of the compass actually has a south polarity but it points to (seeks) north