Electronic circuits usually use direct current sources. The load of an electronic circuit may be as simple as a few resistors, capacitors, and a lamp, all connected together to create the flash in a camera. Or an electronic circuit can be complicated, connecting thousands of resistors, capacitors, and transistors. It may be an integrated circuit such as the microprocessor in a computer.
Electric circuitry is a key component of the National Curriculum, particularly from ages 14, Key Stages 4 onwards. However this is a difficult concept to teach because it of its abstract nature.
Therefore students can have difficulty grasping the ideas and principles involved and constructing understanding. Misconceptions may develop, with students believing electricity is a substance which gets used up. Understanding of electricity involves students acquiring a specialised specific set of vocabulary. However, although we cannot see electrical charges moving and transferring energy, the effect of the transfer can be seen.
Such abstract concepts can be explained using analogies which use familiar words or ideas to represent the ideas which need to be conveyed. Analogies are selected which students should already be familiar with. However, no single analogy can represent all features of an electrical circuit and there are important differences between the analogies used and circuits. Instead appropriate analogies should be chosen to teach selected concepts and students should be prompted to compare analogies with circuits and identify how they differ.