7.4 Magnetic fields

• What are magnetic fields?

  Regions with magnetic force
• Arrange the fields in order of their source:

  1️⃣ Mass (Gravitational Fields)

  2️⃣ Electric Charges (Electric Fields)

  3️⃣ Magnets or Moving Charges (Magnetic Fields)
• The strength of a magnetic field generated by an electric current is proportional to the current's magnitude.


  True
• Closer magnetic field lines indicate a stronger magnetic field.


  True
• Magnetic fields exert force on other magnets and moving charges.


  True
• Arrows on magnetic field lines indicate the direction of the magnetic force.


  True
• What do magnetic field lines indicate in a magnetic field?

  Direction and strength
• What are the sources of magnetic fields?

  Magnets and moving charges
• The source of magnetic fields can be magnets or moving charges.
• The magnetic force on a charged particle is perpendicular to both its velocity and the magnetic field lines.
• The magnetic force on a charged particle is denoted by the letter F.
• Match the type of force with its key properties:

  Magnetic Force ↔️ Perpendicular to velocity and field

  Electric Force ↔️ Parallel to electric field

  Gravitational Force ↔️ Always attractive
• What are magnetic fields represented by?

  Field lines
• What direction do magnetic field lines outside a magnet follow?

  North to South pole
• From what sources do magnetic fields arise?

  Magnets, moving charges
• Electric currents generate magnetic fields due to the movement of electric charges.


  True
• Magnetic field lines emerge from the north pole and curve back to the south pole outside the magnet.


  True
• When a charged particle moves through a magnetic field, it experiences a magnetic force
• Magnetic field measurements are expressed in Tesla (T) or Gauss
• Magnetic data storage relies on the ability to magnetize and detect magnetic domains
• Magnetic fields arise from magnets or moving charges, while gravitational fields arise from mass.


  True
• Magnetic fields can arise from electric currents or electron spin
• Magnetic field lines flow from the north pole to the south pole
• Magnetic fields arise from magnets or moving electric charges
• When many electron spins align, they create a strong magnetic field
• Arrange the fields in order of their direction convention:

  1️⃣ Positive to Negative (Electric Fields)

  2️⃣ North to South (Magnetic Fields)

  3️⃣ Always Attractive (Gravitational Fields)
• In a uniform magnetic field, the field lines are parallel and equally spaced.


  True
• What do the arrows on magnetic field lines indicate?

  Force direction
• What type of motion does a charged particle undergo in a magnetic field if its velocity is perpendicular to the field lines?

  Circular motion
• What is the equation relating the magnetic force on a charged particle to its charge, velocity, magnetic field strength, and angle between velocity and field?

  $F =$$qvB\sin\theta$
• What is the key difference between magnetic force, electric force, and gravitational force on charged particles?

  Their source and direction
• Magnetic fields arise from the movement of electric charges or electron spin.


  True
• Magnetic fields originate from magnets or moving charges, while electric fields originate from electric charges.


  True
• Closer magnetic field lines indicate a stronger magnetic field.

  True
• What are the two main sources of magnetic fields?

  Electric currents and electron spin
• A uniform magnetic field has parallel, equally spaced magnetic field lines
• The direction of gravitational fields is always attractive.


  True
• The magnetic force on a charged particle is perpendicular to both its velocity and the magnetic field lines.

  True
• What type of magnetic field is used in Magnetic Resonance Imaging (MRI)?

  Uniform magnetic fields
• Magnetic fields are represented by field lines