P4.1 Magnets and Magnetic Fields

• What is a magnet?

  A material that produces a magnetic field
• What is a magnetic field?

  Region around a magnet
• What direction does the magnetic field around a current-carrying conductor follow?

  Circles around the conductor
• What is the role of electron spin in creating the magnetic field of a permanent magnet?

  Atoms align to create a field
• Magnetic field lines show the direction and strength of the magnetic field.field
• Magnetic flux measures the amount of magnetic field passing through a surface.field
• The strength of a magnetic field is constant regardless of distance from the magnet.

  False
• Steps to calculate magnetic flux

  1️⃣ Determine magnetic field strength (B)

  2️⃣ Determine area (A) perpendicular to the field

  3️⃣ Determine angle (θ) between field and normal

  4️⃣ Calculate Φ = B ⋅ A ⋅ cos(θ)
• What is the magnetic flux when magnetic field lines are parallel to the surface?

  Minimum
• What is the unit of magnetic flux?

  Weber
• What are the two types of magnetic poles?

  North and South
• What creates a magnetic field?

  Moving electric charges
• What do magnetic field lines represent?

  Direction and strength
• What do magnetic field lines represent?

  Direction and strength
• What is indicated by evenly spaced and parallel magnetic field lines?

  Uniform magnetic field
• Like magnetic poles repel each other.


  True
• Unlike magnetic poles attract each other.


  True
• Magnetic fields are created by moving electric charges.charges
• Match the property of a magnet with its description:

  Magnetic Field ↔️ Region around a magnet

  Attraction/Repulsion ↔️ Unlike poles attract; like poles repel

  Polarity ↔️ Magnets have a north and south pole
• Where is the magnetic field strength of a magnet strongest?

  Near the poles
• What determines whether a magnetic field is uniform or non-uniform?

  Field line spacing
• Describe the characteristics of a uniform magnetic field.

  Parallel, evenly spaced lines
• What is the formula for magnetic flux (\(\Phi\))?

  $\Phi =$$B \cdot A \cdot \cos(\theta)$
• A changing magnetic flux induces an electromotive force (EMF) in a conductor
• Magnetic field strength is measured in teslas
• Unlike magnetic poles attract, while like magnetic poles repel
• A wire carrying electric current generates a magnetic field that circles around the conductor
• Magnetic field strength is strongest near the poles and weaker further away
• Magnetic field strength is uniform throughout the magnet.

  False
• Magnetic flux is the total number of magnetic field lines passing through a given area
• What happens when magnetic flux changes in a conductor?

  EMF is induced
• Where does the magnetic field of a bar magnet extend from?

  North to south pole
• What are the two types of magnetic poles?

  North and south
• A compass needle aligns parallel to magnetic field lines.


  True
• A magnet produces a magnetic field.field
• Arrange the sources of magnetic fields from smallest to largest scale:

  1️⃣ Moving Electric Charge

  2️⃣ Current-Carrying Conductor

  3️⃣ Permanent Magnet
• Changing magnetic fields can induce electric currents.


  True
• How are magnetic fields fundamentally related to electricity?

  Moving electric charges create them
• Uniform magnetic fields have evenly spaced and parallel field lines.


  True
• Magnetic field lines show the path a magnetic compass needle would point along if placed in the field