No circuit is complete without something to use up the energy. This is called the load and can take the form of a motor, resistor, light bulb, electromagnet, heater, etc. In a series circuit current must flow along one pathway only. In a parallel circuit current is given a choice of flowing one pathway or another. The circuit is connected so that current can flow through hone component without having first to flow through another.
Circuit diagrams show circuits represented by symbols.
Power Transistor fuse Circuit diagrams are required for each activity in your interfacing workbook.