PHYSICS

• Magnet


  Can provide the most effective visualization on how electric charges behave in the presence of other charges through magnetic poles

  
• Magnetism


  Originated from Magnesia in Greece, where the ancient Greeks found lodestones that can attract pieces of iron
• Magnetism


  Occurs because of the alignment of atoms, these aligned atoms are called magnetic domains
• Magnetic poles


  Commonly known as the north pole and the south pole of a magnet

  
• Magnetic force


  Causes the repulsion and attraction between magnetic poles

  
• Magnetic poles cannot exist in isolation like electric charges

  
• A north pole will always have a corresponding south pole in the same magnet

  
• Demagnetization of magnets


  1. Hammering

  2. Heating

  3. Being exposed to an alternating current
• Demagnetization


  Involves mixing up the arrangement of molecules to cancel the polarity of the entire material
• Magnetization


  Can be achieved by exposing a demagnetized magnet to another magnet with a strong magnetic field
• Magnetic field


  The region around every magnetic pole where another magnetic pole will experience magnetic interaction

  
• Magnetic field lines


  • A north pole will have field lines drawn from it, and a south pole will have field lines drawn toward it

  
• Dutch scientist Hans Christian Oersted made a discovery about electricity


  1820
• Electromagnetism


  Oersted discovered that electric current or flow of electric charges results in magnetism

  
• Charged particles in motion


  Form a magnetic field around them and can be subjected to a magnetic interaction
• Charged particles at rest cannot be affected by any magnetic field
• Magnetic field around a magnetic pole


  The region where the influence of the pole is evident

  
• Ampere's law


  Shows the relationship between the flowing current through a loop of conductor and the net magnetic field produced in the loop

  
• Whenever current passes through a conductor, a magnetic field is produced

  
• Right-hand rule


  If there is a wire, your thumb aligned along it indicates the direction of the current, and the "curl" of your four fingers around the conductor represents the direction of the magnetic field

  
• Moving away from the electrical conductor decreases magnetic field strength
• Calculating magnetic field around a straight current-carrying conductor


  Use the formula: Magnetic field = (μ0 * I) / (2 * π * r)

  
• Magnetic force


  Attraction or repulsion that arises between electrically charged particles because of their motion
• Right-hand rule for magnetic force

  Thumb points to the direction of the charge or the direction of conventional current, four fingers point to the direction of the magnetic field, and the palm points to the direction of the magnetic force

  
• Calculating magnetic force between parallel wires

  Use the formula: F = (μ0 * I1 * I2 * L) / (2 * π * d)

  
• Solenoid


  A long coil of wire that is wrapped around a core to form a helix, the basic foundation of most modern technologies that makes use of the concept of magnetism

  
• Calculating magnetic field within a solenoid

  Use the formula: B = (μ0 * N * I) / L

  
• Electromagnetic induction


  The production of current in a conductor as it moves through a magnetic field
• Relative permeability


  A quantity that relates the magnetic field in a material to the magnetic field in a vacuum

  
• Magnetic flux


  The strength of the magnetic field around a magnetic pole, measured in Webers (Wb)

  
• Calculating magnetic flux


  Use the formula: Φ = B * A

  
• Faraday's law


  The induced EMF in a coil is proportional to the number of loops in the coil and the rate of change of the magnetic flux within the coil loops

  
• Calculating average induced EMF in a coil

  Use the formula: ε = -N * (ΔΦ/Δt)