7.4 Magnetic fields

• What is a magnetic field?

  Region with magnetic force
• Match the property with its corresponding value for magnetic and electric fields:

  Representation ↔️ Magnetic field lines ||| Electric field lines

  Direction ↔️ Tangent to field lines
• The density of magnetic field lines indicates the field's strength
• What are the two main sources of magnetic fields?

  Moving charges, permanent magnets
• Match the property with its correct source of magnetic field:

  Source ↔️ Moving electric charges ||| Permanent magnets

  Persistence ↔️ Temporary ||| Persistent
• Magnetic field lines from permanent magnets are directed from the north pole to the south pole.
• Arrange the following properties of magnetic field lines in a logical order:

  1️⃣ Continuous loops

  2️⃣ Direction indicated by tangent

  3️⃣ Strength represented by density
• How do magnetic field lines differ from electric field lines in terms of their shape?

  Continuous loops
• The density of magnetic field lines represents the strength
• The tangent to a magnetic field line at any point indicates the direction of the magnetic field.


  True
• What is the source of a magnetic field according to electromagnetism?

  Moving electric charges
• Magnetic field lines inside a permanent magnet are directed from the north pole to the south pole.


  True
• What is the direction of magnetic field lines created by permanent magnets?

  North to south
• Match the property with its source of the magnetic field:

  Moving electric charges ↔️ Circular field lines

  Permanent magnets ↔️ North to south direction
• The magnetic force on a moving charge is given by the equation F = qvB.
• What rule is used to determine the direction of the force on a moving charge in a magnetic field?

  Right-hand rule
• What is magnetic force exerted on?

  Moving charges or current-carrying conductors
• Steps to determine the direction of magnetic force on a current-carrying conductor using the right-hand rule.

  1️⃣ Point your thumb in the direction of the current

  2️⃣ Point your fingers in the direction of the magnetic field

  3️⃣ Your palm shows the direction of the force
• The force on a current-carrying conductor is parallel to the magnetic field.

  False
• What are the parameters in the equation F = qvB?

  Charge, velocity, magnetic field
• What do magnetic field lines represent?

  Direction and strength
• The source of a magnetic field can be stationary electric charges.

  False
• What direction do magnetic field lines travel outside a permanent magnet?

  North to South
• Magnetic field lines have a beginning and an end like electric field lines.

  False
• The strength of a magnetic field is measured in units of tesla or newtons per ampere-meter
• The strength of a magnetic field is measured in units of tesla
• Match the properties of magnetic and electric fields:

  Direction ↔️ Tangent to field lines

  Strength ↔️ Density of field lines
• The direction of magnetic force on a moving charge is perpendicular to both velocity and magnetic field.

  True
• The right-hand rule is used to determine the direction of magnetic force on a current-carrying conductor.


  True
• The magnetic field around a straight wire forms concentric circles
• The field strength inside a solenoid is proportional to the number of turns
• Arrange the applications of magnetic fields by their primary function:

  1️⃣ Motors: Convert electrical to mechanical energy

  2️⃣ Generators: Convert mechanical to electrical energy

  3️⃣ Transformers: Change voltage in AC circuits

  4️⃣ MRI: Image body using strong magnetic fields
• Maglev trains use magnetic repulsion to levitate above the track.

  True
• Magnetic fields and electric fields are identical in all properties.

  False
• What is the source of a magnetic field?

  Moving electric charges, magnets
• Magnetic field lines have a starting and ending point.

  False
• Inside a permanent magnet, magnetic field lines are directed from the north pole to the south pole.
• A magnetic field from moving charges is temporary.


  True
• What are magnetic field lines used to represent?

  Direction and strength of field
• Magnetic field lines can begin or end at charges, similar to electric field lines.

  False