Magnetic Fields

• At which part of magnet are the magnetic forces strongest?

  The poles of the magnet.
• What happens when 2 magnets are brought close to each other?

  They exert a force on each other.
• What type of force is exerted if 2 like poles of a magnet are brought near each other?

  A repulsive, non-contact force.
• What type of force is exerted if 2 unlike poles of a magnet are brought near each other?

  An attractive, non-contact force.
• What is a magnetic field?

  The region surrounding a magnet where another magnet or magnetic material experiences a non-contact force.
• What is the difference between a permanent magnet and an induced magnet?

  A permanent magnet produces its own magnetic field. An induced magnet becomes magnetic when placed in a magnetic field.
• What type of force does induced magnetism always cause?

  A force of attraction.
• What is the effect when an induced magnet is removed from a magnetic field?

  The induced magnet loses most/all of its magnetism.
• Give 4 examples of magnetic materials.

  Iron, Steel, Cobalt and Nickel.
• What can always be said about the force between a magnet and a magnetic field?

  It is always attractive.
• How does the strength of a magnetic field alter as you move further away from the magnet producing it?

  The magnetic field strength decreases the further you move away.
• In what direction does a magnetic field point?

  In the direction of the force that a north pole would experience if placed in the field. From the north seeking pole to the south seeking pole of a magnet.
• What does a magnetic compass contain?

  A small bar magnet that points in the direction of the Earth's magnetic field.
• What is produced when a current flows through a conducting wire?

  A magnetic field is produced around the wire.
• What determines the strength of the magnetic field around a current-carrying wire?

  The magnitude of the current flowing through the wire.
• Does a high concentration of field lines mean the field is strong or weak?

  Strong.
• True or false: magnetic field lines never cross each other?

  True; they never cross, touch or overlap.
• How is a plotting compass used to map out a magnetic field?

  Place a compass (containing a needle magnet) on a piece of paper near the field. Draw an arrow in the direction the compass points. Repeat at different points on the paper. Join the arrows to make a complete field pattern.
• What is a solenoid?

  A coil of wire which when current passes through creates a strong magnetic field.
• Describe the magnetic field found inside a solenoid>

  Strong and uniform.
• Is the field on the outside of a solenoid strong or weak? And why?

  Weak.

  The fields from each coil cancel out, making the outside field weak.