Resource 1: Common Misconceptions
Background information / subject knowledge for teacher
Misconceptions about magnets and magnetism
Researchers have discovered that there are certain misconceptions about electricity and magnetism that are very common. We have summarised them here, so that when you plan your lessons, you can make sure that you address these misconceptions.
Misconception: all metals are attracted to a magnet
Not all metals are attracted to a magnet. Copper, aluminium, gold and silver are all metals, but they aren’t attracted by a magnet. Iron, steel, nickel and cobalt are. Alloys containing these metals can also be attracted to a magnet – ‘copper coins’ attracted to a magnet are not actually copper but a copper–nickel alloy.
Misconception: if something is attracted by a magnet, it is a magnet
Being attracted to a magnet does not mean that a material is a magnet (but it is a magnetic material and can be made into a magnet). If something is attracted to a magnet, turn the magnet round and try again: if the object is repelled by the magnet this time, then the object is a magnet, too.
Misconception: the Magnetic North Pole, i.e. the pole of the earth in the northern hemisphere, is magnetically a north pole
North poles of magnets are the poles that point to the north. Like poles repel, unlike poles attract, so the Earth’s Magnetic North Pole is actually a magnetic south pole, because it attracts the north pole of a magnet!
Misconceptions about circuits and electricity
Misconception: you only need one wire to make a circuit with a battery and a bulb
If students have seen an electric light hanging by a cord from the ceiling or electrical equipment with a lead to a plug, but have never constructed a circuit with batteries and bulbs, then they may think this. (They may also think that if you use two wires, the wire from one end of the battery is the one that counts and the other one is just there as a ‘return route’.) There must be a connection from each end of the battery to two points on the bulb holder (i.e. the metal, not the glass) for the bulb to light.
Misconception: current is ‘used up’ as it flows round the circuit
Current is not used up: the current is the same all the way round a series circuit. If current is used up, then bulbs near the ‘start’ of the circuit should be brighter than those near the ‘end’. Providing the bulbs are identical, then they will all be the same brightness.
Misconception: current starts from one end of a battery and flows through each component of a circuit in turn, until it gets back to the other end of a battery (e.g. battery to wire, then bulb, then wire, then bulb, then wire back to battery)
Current flows instantly in all parts of a circuit when there is a complete circuit. Even if you had a huge circuit going right round the classroom, all the bulbs in it would light up at the same time, not one after the other.