Schematics use symbols to represent components in the circuit. Conventions are used in a schematic to represent the way electricity flows. The common convention we use is from the positive to the negative terminal. The realistic way electricity flows is from the negative to the positive terminal.
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.
The electrons enters from a point to an electrical circuit which is called the “source” of electrons or “electrons source” . The point where electrons leaves the circuit is called ground or earth(in some concepts it is also know as “return”).
During project days or workshops contact time with students is limited. It is therefore important for us to quickly ascertain student level of knowledge and then build on it or reinforce it. Analogies provide a good method of finding out students pre-existing level of understanding on this topic.