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
• Which celestial body acts as a giant magnet with north and south magnetic poles?

  Earth
• 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 the two poles every magnet has?

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

  False
• The source of magnetic fields can be moving electric charges or magnets
• What causes the magnetic field in permanent magnets?

  Aligned electron spins
• Permanent magnets have a relatively strong and constant magnetic field strength
• What is an example of a common material used in permanent magnets?

  Alnico
• Match the property with the correct source of magnetic fields:

  Permanent Magnets ↔️ Aligned electron spins

  Moving Electric Charges ↔️ Electric current in a wire

  Magnetic Field Direction ↔️ Fixed north-south orientation
• Electric currents provide a versatile way to create magnetic fields that can be adjusted through current control
• Magnetic field lines point from the south pole to the north pole of a magnet.

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


  True
• What acts as a giant magnet with north and south magnetic poles?

  The Earth
• Permanent magnets maintain a magnetic field without external assistance.
• What is a common example of a permanent magnet material?

  Alnico
• What is the relationship between the strength of the magnetic field and the current in a wire?

  Proportional
• What are the two factors that affect the strength of the magnetic field around a current-carrying wire?

  Current magnitude and distance
• When an electric current flows through a wire, it generates a magnetic field around the wire.
• What does Faraday's Law state about electromagnetic induction?

  Induced emf equals rate of change of 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
• What causes the magnetic field in permanent magnets?

  Aligned electron spins
• What is an example of a material used in permanent magnets?

  Alnico
• Like magnetic poles attract each other.

  False
• Magnetic fields are regions of space where magnetic forces
• What type of poles do magnetic fields have?

  North and south
• 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
• What is the relationship between the strength of the magnetic field around a wire and the current flowing through it?

  Proportional
• How do you determine the direction of the magnetic field around a current-carrying wire?

  Right-hand rule
• What is a key characteristic of magnetic field lines?

  Continuous loops
• 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