electromagnetism

magnetic: any material that can be attracted by magnets.

magnetism: if the force displayed by magnets which allows materials to repel or attract. 

attraction: the force that can pull the magnet together

repulsion: the force that can push the magnets apart

magnetic domains: areas within a material where the magnetic fields of atoms are aligned in the same direction, which makes it magnetized. 

magnetic field: the space around a magnet where the magnetic force can have an effect

  • the arrows show the direction of the field

  • goes out the north and in through the south

  • the further the spacing of the lines are, the weaker the force


unmagnetized: when the magnetic domains are pointing in random directions. 

magnetized: when an object has become magnetic, with atoms aligning to create a magnetic field. 

permanent magnet: a material that keeps its magnetic properties over time and always has a south and north pole. 

temporary magnet: a material that only becomes magnetic when its in a magnetic field, but loses its magnetism once the field is removed. 


  • magnetism is a non-contact force

  • iron, nickel, steel, cobalt are attracted to magnets 

  • opposite poles attract and like poles repel because the lines of force are in opposite directions

  • domains also have a north and south pole like a normal magnet. 

  • only magnetic materials can be magnetized

  • non-magnetic materials either have no magnetic domains or their domains are fixed in random directions


two relationships in electromagnetism: 

  • electric currents produce magnetic fields 

  • changing magnetic fields can produce electric currents


electromagnet: a type of magnet that becomes magnetic when an electric current flows through it, but loses magnetism when the current is turned off. 

  • the magnetic field of an electric current is even stronger when it is bent into a coil shape

  • the magnetic force is especially strong in the centre of the coil

  • adding more coils increases the magnetic force

  • the magnetic field of a straight piece is weaker because the force spreads out along the length of the wire

  • the magnetic field of coils are stronger because the loops work together to concentrate the magnetic field in the centre, making it stronger

  • electric currents can also be used to turn other objects into electromagnets. 

electrical current: 


  • electric current in a metal wire involves the flow of electrons 

  • higher the current, the faster they move

  • terminals transfer energy to components such as light bulbs and motors

  • higher the voltage, the more energy is provided to the electrons moving in a circuit

  • resistance is measured in ohms

  • the current depends on the voltage in any circuit

  • higher voltage = higher current


what we need for basis of electrical current: 

  • it must have a closed pathway, or circuit, to flow around

  • it must hve an energy source such as a power station, generator or battery which causes the current to flow

  • it must flow through certain parts or components, of the circuit that can use the energy for something useful such as a light bulb or motor

three ways to make electromagnet stronger: 

  • more turns on the coil 

  • more electrical current 

  • using an iron core


current: flow of electrons 

ammeter: device that measures current

ampere/amp: unit of electrical current

terminals: points where electrical connections are made, like the ‘entry’ and ‘exit’ points for electricity

voltages/volts (V): a measure of how much energy is given to the moving electrons in a circuit or the amount of push

resistor: an electrical component that limits the flow of electrical current in an electronic circuit. 


parallel circuit: has two or more paths for current to flow through

  • the current that leaves the cell is the same as the current that returns to the cell

  • if the bulbs are identical then the current will split evenly, if they are not then the current will not split evenly

  • current is divided, voltage is constant 

  • higher resistance = lower current



series circuit: in which all circuit elements are arranged in a single path

  • voltage is divided, current is constant 

  • the sum of voltage across each component is the same as the total supply voltage

  • higher resistance = lower current


short circuit: when an electric current flows down the wrong or unintended path with little to no electrical resistance

  • voltage is very low, because of little resistance 

  • current is very high