6.3 Electromagnetism

• A magnetic field in an area in which a charged object experiences a force
• Magnetic fields are created by permanent magnets or by a current carring conductor
• The arrow on a magnetic field line shows the direction of flow of magnetic flux, or the direction in which a north pole would move
• A uniform field has equally spaced, parallel field lines
• Magnetic fields are strongest where magnetic flux density is greatest, which is where magnetic field lines are closest
• The right hand grip rule is used for a solenoid where the thumb points in the direction of the current, and the fingers curl in the direction of the magnetic field
• Placing a current carrying conductor in an external magnetic field causes the magnetic fields to interact and cause equal and opposite forces
• F=BILsinθ

  F= force

  B= magnetic flux density

  I= current

  θ= angle made with the direction of magnetic flux
• Magnetic flux is measured in Teslas (T) and has base units of $Nm^{-1}A^{-1}$