2.4.1 Magnetic Fields

• Magnetic fields are represented by invisible lines showing their strength and direction
• Magnetic field lines always form complete closed loops.

  True
• Magnetic field lines are denser near the poles where the magnetic force is stronger.


  True
• What happens to magnetic field lines near the north and south poles?

  They become denser
• Magnetic domains in magnetic materials align with the external magnetic field
• Where are magnetic field lines most concentrated in a magnetic field?

  Near the poles
• Magnetic field lines always form complete closed loops with no beginning or end.

  True
• What does the density of magnetic field lines indicate?

  Field strength
• Magnetic materials are attracted to magnets because their magnetic domains align
• Why do magnets create magnetic fields?

  Alignment of atomic magnetic moments
• The source of a magnetic field in a magnet is the alignment of atomic magnetic moments
• The strength of a magnetic field created by a magnet depends on the material's properties
• Arrange the following properties of magnetic field lines in a logical order:

  1️⃣ Lines emerge from the north pole

  2️⃣ Lines enter the south pole

  3️⃣ Lines are denser near the poles

  4️⃣ Lines form complete closed loops
• What two properties of magnetic fields are shown by magnetic field lines?

  Strength and direction
• Where is the magnetic force strongest in a magnetic field?

  Near the poles
• Magnetic field lines emerge from the north pole and enter the south pole.


  True
• Why are non-magnetic materials unaffected by magnetic fields?

  Atoms do not align
• From which pole do magnetic field lines emerge?

  North pole
• What do magnetic field lines represent in a magnetic field?

  Strength and direction
• Magnetic field lines circulate within and around magnets.


  True
• Non-magnetic materials are unaffected by magnetic fields because their magnetic moments are not aligned.


  True
• Steps involved in the generation of a circular magnetic field by an electric current

  1️⃣ Electric current flows through a conductor

  2️⃣ Circular magnetic field is generated around the wire

  3️⃣ Direction of field determined by current flow
• The magnetic field created by an electric current is circular around the conductor.


  True
• The strength of a magnetic field created by an electric current depends on the magnitude of the current.


  True
• From which pole do magnetic field lines emerge?

  North pole
• Magnetic field lines emerge from the north pole and enter the south
• Magnetic field lines always form complete closed loops
• What happens to magnetic domains in a magnetic material when exposed to a magnetic field?

  They align
• Magnetic field lines form closed loops and emerge from the north pole.


  True
• The magnetic field is strongest where the field lines are most dense
• Magnetic field lines emerge from the north pole and enter the south pole of a magnet
• What happens to magnetic domains in a magnetic material when exposed to a magnetic field?

  They align
• What are the two main sources of magnetic fields?

  Magnets and electric currents
• What is the shape of the magnetic field created by a magnet?

  Radial field lines
• What determines the direction of the magnetic field created by an electric current?

  Direction of current flow
• Match the application with its use of magnetic fields:

  Electric Motors ↔️ Generate rotational force

  Magnetic Resonance Imaging (MRI) ↔️ Detailed medical imaging

  Magnetic Data Storage ↔️ Store digital data

  Magnetic Compasses ↔️ Determine direction