Magnets and Electromagnets

• The magnetic field is the region of space around a magnet where a magnetic material will experience a force.
• Like poles repel, unlike / opposite poles attract.
• The strength of a magnetic field decreases as you get further away from the magnet.
• The magnetic field is strongest at the magnet's poles.
• Magnetic field lines point north to south.
• The distance between magnetic field lines indicates the strength of the magnetic field, the closer together they are, the stronger the magnetic field.
• A permanent magnet is a material that produces its own magnetic field.
• An induced magnet is a material that becomes magnetic when it is put in a magnetic field.
• A magnetic compass contains a small bar magnet.
• A magnetic field is produced around a wire when an electric current flows through it.
• The strength of the magnetic field around a straight wire depends on the size of current and the distance from the wire.
• A cylindrical coil of wire acting as a magnet when carrying electric current is called a solenoid.
• Shaping a wire into a solenoid increases the strength of the magnetic field.
• Placing an iron core inside a solenoid increases the magnetic field strength.
• Fleming's left hand rule shows the relative orientation of the force, current in the conductor and magnetic field for the motor effect.
• The unit for magnetic flux density is tesla (T) and the symbol is B.
• The motor effect is when a conductor placed in a magnetic field experiences a force.
• The motor effect is caused by the interaction between the magnetic field created by current in a wire and the magnetic field in which the wire is placed.