7.1 Permanent & Induced Magnetism, Magnetic Forces & Fields

• What are the ends of a magnet called?

  Poles
• How many poles do magnets have?

  Two
• What happens when opposite poles of magnets are brought together?

  They attract each other

  
• What does the Law of Magnetism state about like poles?

  They repel each other

  
• What does the Law of Magnetism state about unlike poles?

  They attract each other
• What type of force is the attraction or repulsion between magnetic poles?

  Non-contact force

  
• What materials are attracted to magnets?

  Magnetic materials
• Which metals are considered magnetic?

  Iron, Cobalt, Nickel
• Why is steel considered magnetic?

  It contains iron
• How can you test if a material is a magnet?

  Bring it close to a known magnet
• What indicates that a material is a magnet when tested with a known magnet?

  It can be repelled
• What happens if a material is only attracted and not repelled by a magnet?

  It is a magnetic material
• What are the two types of magnets?

  • Permanent magnets
  • Induced magnets
• What are permanent magnets made from?

  Permanent magnetic materials
• What does a permanent magnet do?

  Produces its own magnetic field
• What is induced magnetism?

  Temporary magnetism in a magnetic material
• What happens to a magnetic material placed in a magnetic field?

  It becomes a magnet temporarily

  
• What occurs at each end of a magnetic material when it is magnetized?

  One end becomes a north pole, the other a south pole

  
• What happens to a magnetic material when it is removed from a magnetic field?

  It loses most/all of its magnetism quickly
• What is the definition of a magnetic field?

  Region around a magnet where force acts
• How are magnetic field lines used?

  To represent strength and direction of a magnetic field
• What do closely spaced magnetic field lines indicate?

  Strong magnetic field
• What do widely spaced magnetic field lines indicate?

  Weak magnetic field
• What is the direction of magnetic field lines?

  From north to south

  
• What happens to magnetic field lines when they cross?

  They must never touch or cross
• Where is the magnetic field strongest around a bar magnet?

  At the poles
• How does the strength of the magnetic field change with distance from the magnet?

  It becomes weaker as distance increases
• What are the characteristics of a uniform magnetic field?

  • Same strength at all points
  • Same direction at all points
  • Equal spacing between magnetic field lines
• How is a uniform magnetic field created?

  By holding opposite poles close together
• What indicates the direction of a magnetic field line?

  Force acting on another north pole
• How can the shape and direction of a magnetic field be investigated?

  Using plotting compasses
• What does the arrow of a plotting compass represent?

  The north pole of the compass
• What is the first step in investigating the shape of a magnetic field?

  Place the magnet on paper
• What should you do after placing the plotting compass next to the dot?

  Draw a new dot at the other side of the compass needle
• What should you do after creating a chain of dots?

  Link the dots using a smooth curve
• What does the plotting compass method visualize?

  The magnetic field around a magnet

  
• What does a magnetic compass point to on Earth?

  North
• Why does a compass point north?

  Earth's core is magnetic
• What is the relationship between the geographic North Pole and Earth's magnetic field?

  Geographic North Pole is a magnetic south pole

  
• What happens to the north pole of a compass at the geographic South Pole?

  It is repelled from the magnetic north pole