magnetisms

• What can a magnet exert on another nearby magnet?

  A force
• What are the two poles of a magnet?

  North pole and south pole
• Where is the magnetic force strongest on a magnet?


  Near the magnet's poles
• What are the rules of magnetism regarding attraction and repulsion?

  • Like poles (N-N or S-S) repel
  • Unlike poles (N-S or S-N) attract
• What type of forces are magnetic forces?

  Non-contact forces
• Which materials are considered magnetic materials?

  Iron, steel, nickel, and cobalt
• What is a permanent magnet made from?

  A magnetic material such as iron
• What is a key feature of a permanent magnet?

  It produces its own magnetic field
• Can the magnetic field of a permanent magnet be turned off?

  No, it is always present
• What are examples of permanent magnets?

  Bar magnets and horseshoe magnets
• When does an induced magnet become magnetized?

  When placed in a magnetic field
• What happens to iron filings near a bar magnet?

  They become induced magnets
• What happens to induced magnets when removed from a magnetic field?

  They lose most or all of their magnetism
• How can you confirm that an object is a permanent magnet?

  By checking if it repels another magnet
• What is a magnetic field?

  Region around a magnet where force acts
• What does a compass contain?

  A small bar magnet on a pivot
• What are the steps to map out magnetic fields using plotting compasses?

  1. Place the compass near the magnet on paper
  2. Mark the direction the needle points
  3. Move the compass to different positions, marking each direction
  4. Join the points to show field lines
• To which pole of the magnet does the needle of a plotting compass point?

  To the south pole of the magnet
• What materials make up the Earth's core?

  Iron and nickel
• What are the key features of the magnetic field around a bar magnet?

  • Magnetic field lines never cross each other
  • Closer lines indicate a stronger magnetic field
  • Arrowheads show the direction of the force
  • Arrowheads point from north to south pole
• What does a current flowing in a wire create?

  A circular magnetic field
• What happens to the strength of the magnetic field if the current is increased?

  The strength of the magnetic field increases
• What is a solenoid?

  • A wire coiled into a spiral shape
  • Creates a magnetic field when current flows
• How does the magnetic field of a solenoid compare to that of a bar magnet?

  It is very similar to the field of a bar magnet
• What is the nature of the magnetic field inside a solenoid?

  It is strong and uniform
• What is a solenoid with an iron core called?

  Electromagnet
• How does an iron core affect a solenoid's magnetic field strength?

  It increases the magnetic field strength
• What are some applications of electromagnets?

  • Electric bells
  • Door locks controlled remotely
• What does a wire carrying a current create?

  A magnetic field
• What is the term for the force that pushes a wire at right angles?

  The motor effect
• What units are used for magnetic flux density?

  Tesla (T)
• What is Fleming's left hand rule used for?

  Determining the direction of motor effect force
• What happens to the force on a wire in a magnetic field when the current increases?

  The force increases
• How does the strength of the magnetic field affect the force on a wire?

  The force increases with stronger magnetic fields
• When is the force on a wire greatest in a magnetic field?

  When current is 90 degrees to the magnetic field
• What is the condition for no motor effect force to occur?

  When current and magnetic field are parallel
• What happens to a coil of wire carrying a current in a magnetic field?

  It experiences a force that tends to make it rotate
• How can the effect of a rotating coil in a magnetic field be utilized?

  It can be used to make an electric motor
• What direction does the current in the left part of the coil cause the force to act in an electric motor?

  Downward
• What direction does the current in the right part of the coil cause the force to act in an electric motor?

  Upward