Magnets

• How would a compass needle behave in a magnetic field?

  It aligns with the magnetic field lines
• What is a magnetic field?

  An invisible area around a magnet
• What do closely packed field lines indicate in a magnetic field diagram?

  • Stronger magnetic force
  • Greater interaction with magnetic objects
• What are the key differences between a permanent magnet and an electromagnet?

  Permanent magnet:

  • Produces a constant magnetic field
  • Made of magnetic materials like iron, nickel, cobalt

  
  

  Electromagnet:

  • Produces a magnetic field only when electric current flows through it
  • Can be turned on and off
  • Strength can be controlled by adjusting the current
• What happens to the force as field lines become more packed together?

  The force becomes stronger
• How can the direction of a magnetic field be determined?

  • Use a compass: the north pole of the compass will point in the direction of the magnetic field lines
  • Apply the right-hand rule: if the fingers of the right hand are curled in the direction of the current, the thumb will point in the direction of the magnetic field
• How do magnetic field lines indicate the strength of the magnetic force?

  Closer lines show stronger magnetic force
• Where do magnetic field lines loop back to?

  They loop back to the south (S) pole
• What are the key differences between a permanent magnet and an electromagnet?

  Permanent magnet:

  • Produces a constant magnetic field
  • Made of magnetic materials like iron, nickel, cobalt

  
  

  Electromagnet:

  • Produces a magnetic field only when electric current flows through it
  • Can be turned on and off
  • Strength can be controlled by adjusting the current
• What is the direction of magnetic field lines outside a magnet?

  From the north pole to the south pole
• In which direction do magnetic field lines flow outside a magnet?

  From north (N) to south (S) poles
• What are the labels on the two ends of the object in the image?

  S and N
• How do the magnetic field patterns differ between unlike pole attraction and like pole repulsion?

  • Unlike pole attraction: Magnetic field lines point from N to S
  • Like pole repulsion: Magnetic field lines point away from each pole
• From which pole do the magnetic field lines spread out?

  North pole (N)
• If the central symbol represents the north pole of a magnet, which direction would the south pole be located?

  Opposite the north pole
• How does the magnetic field around a bar magnet behave?

  • The magnetic field lines emerge from the north pole and re-enter at the south pole
  • The field lines are strongest near the poles and weaker further away
  • The field lines form closed loops around the magnet
• What are the two types of magnetic pole attraction shown in the image?

  Unlike pole attraction and like pole repulsion
• How does unlike pole attraction work in a magnetic field?

  • The magnetic field lines point from the north pole to the south pole
  • Opposite poles (N and S) are attracted to each other
  • This creates a pull between the two poles
• If you wanted to create a stronger magnetic field, would you use a permanent magnet or an electromagnet?

  Electromagnet
• What are the key features of a magnetic field?

  • Originates from a magnetic source (e.g. magnet, electric current)
  • Exhibits field lines that form closed loops
  • Stronger near the magnetic source, weaker further away
  • Exerts a force on magnetic materials and moving electric charges
  • Can be visualized using iron filings or a compass
• What does the pattern of magnetic field lines indicate about the magnetic force?

  It acts equally in all directions
• If you had two bar magnets and placed them so that their north poles were facing each other, what would happen?

  The north poles would repel each other
• What are the labels on the two ends of the object in the image?

  S and N
• In which direction do magnetic field lines run outside the magnet?

  From north to south
• If you wanted to create a stronger magnetic field, would you use a permanent magnet or an electromagnet?

  Electromagnet
• Where do the magnetic field lines converge?

  South pole (S)
• What do magnetic field lines indicate about the flow of magnetic fields?

  • Flow from north pole to south pole outside
  • Flow from south pole to north pole inside
• What does the image accompanying the explanation of magnetic field lines illustrate?

  Arrows indicating N to S flow outside
• What do magnetic field lines around a bar magnet form?

  A symmetrical pattern
• How are forces in a magnetic field represented in diagrams?

  By field lines
• Where do Earth's magnetic field lines exit?

  They exit at the magnetic North Pole
• What are the key differences between a permanent magnet and an electromagnet?

  Permanent magnet:

  • Produces a constant magnetic field
  • Made of magnetic materials like iron, nickel, cobalt

  
  

  Electromagnet:

  • Produces a magnetic field only when electric current flows through it
  • Can be turned on and off
  • Strength can be controlled by adjusting the current
• What does the spacing of magnetic field lines indicate?

  Closer lines show greater field strength
• How does Earth's magnetic field differ from compass labeling?

  Compass N/S labeling is different from magnetic poles
• How does the magnetic force of a horseshoe magnet compare to a bar magnet?

  It shows a stronger force than a bar magnet
• What do field lines in a magnetic field represent?

  The direction and strength of the force
• What do magnetic field lines represent?

  They represent the force paths and direction
• How does like pole repulsion work in a magnetic field?

  • The magnetic field lines point away from each pole
  • Same poles (N and N or S and S) are repelled from each other
  • This creates a push between the two poles
• What do the arrows around the object in the image represent?

  Magnetic field lines
• How do magnetic field patterns vary?

  They vary depending on magnet shape