12.2 Sources of Magnetic Fields

• Permanent magnets are a source of magnetic fields.


  True
• Match the type of magnetic field source with its characteristic:

  Moving electric charges ↔️ Create fields with loops

  Permanent magnets ↔️ Maintain fields without external assistance
• What are the two types of magnetic poles?

  North and south
• Permanent magnets have a constant and relatively strong magnetic field
• What type of poles do magnets have?

  North and south
• In what direction do magnetic field lines point outside a magnet?

  North to south
• What are magnetic fields?

  Regions of magnetic force
• Electric currents produce magnetic fields
• What do magnetic field lines represent?

  Direction and strength
• Magnetic field lines form continuous loops without a beginning or end.

  True
• Like magnetic poles repel each other.


  True
• What causes the magnetic field in permanent magnets?

  Aligned electron spins
• Magnetic field lines point from the north pole to the south pole of a magnet.

  True
• Magnetic field lines always form continuous loops
• What are the two poles every magnet has?

  North and south
• Magnetic field lines have a beginning and an end.

  False
• Match the magnetic property with its description:

  Every magnet ↔️ Has a north and south pole

  Like magnetic poles ↔️ Repel each other

  Earth acts as a ↔️ Giant magnet
• What happens when the north pole of one magnet is brought near the south pole of another magnet?

  They attract
• Match the characteristic of permanent magnets with its description:

  Magnetic Field Strength ↔️ Constant and relatively strong

  Cause of Magnetic Field ↔️ Aligned electron spins in atoms

  Pole Orientation ↔️ Fixed with north and south poles
• The direction of the magnetic field around a current-carrying wire follows the right-hand rule
• How do you determine the direction of the magnetic field around a current-carrying wire?

  Right-hand rule
• What is the shape of magnetic field lines outside a magnet?

  Continuous loops
• What are the two types of magnetic poles in a magnet?

  North and south
• What are magnetic fields represented by?

  Magnetic field lines
• Permanent magnets maintain a magnetic field without external assistance.
• The direction of magnetic field lines around a current-carrying wire follows the right-hand rule.
• Steps to determine the direction of the magnetic field around a current-carrying wire using the right-hand rule:

  1️⃣ Point your right thumb in the direction of the current

  2️⃣ Curl your fingers around the wire

  3️⃣ Your fingers indicate the direction of the magnetic field lines
• Magnetic monopoles have been experimentally confirmed to exist.

  False
• Lenz's Law explains that the induced current opposes the change in magnetic flux.
• How do moving electric charges generate magnetic fields?

  They align electron spins
• Electromagnetic induction involves the generation of electric fields by changing magnetic fields.


  True
• The source of magnetic fields can be moving electric charges or magnets
• Magnetic field lines are denser in regions where the magnetic field is stronger
• Which celestial body acts as a giant magnet with north and south magnetic poles?

  Earth
• What is an example of a material used in permanent magnets?

  Alnico
• Like magnetic poles attract each other.

  False
• Magnetic field lines are denser where the magnetic field is stronger.


  True
• What is the source of magnetic fields according to the table?

  Moving electric charges
• Magnetic field lines point from the north pole to the south pole
• Magnetic field lines start at positive charges and end at negative charges.

  False