Representing electric circuits, Grade 10 Physics 1/ Components of electrical circuits Some common elements (components) which can be found in electrical circuits include light bulbs, batteries, connecting leads, switches, resistors, voltmeters and ammeters. You will learn more about these items in later sections, but it is important to know what their symbols are and how to represent them in circuit diagrams. Below is a table with the items and their symbols: 2/ Circuit diagrams Definition: Representing circuits A physical circuit is the electric circuit you create with real components. A circuit diagram is a drawing which uses symbols to represent the different components in the physical circuit. We use circuit diagrams to represent circuits because they are much simpler and more general than drawing the physical circuit because they only show the workings of the electrical components. You can see this in the two pictures below. The first picture shows the physical circuit for an electric torch. You can see the light bulb, the batteries, the switch and the outside plastic casing of the torch. The picture is actually a cross-section of the torch so that we can see inside it. Figure 10.1: Physical components of an electric torch. The dotted line shows the path of the electrical circuit. Below is the circuit diagram for the electric torch. Now the light bulb is represented by its symbol, as are the batteries, the switch and the connecting wires. It is not necessary to show the plastic casing of the torch since it has nothing to do with the electric workings of the torch. You can see that the circuit diagram is much simpler than the physical circuit drawing! Series and parallel circuits There are two ways to connect electrical components in a circuit: in series or in parallel. Definition: Series circuit In a series circuit, the charge has a single path from the battery, returning to the battery. Definition: Parallel circuit In a parallel circuit, the charge has multiple paths from the battery, returning to the battery. The picture below shows a circuit with three resistors connected in series on the left and a circuit with three resistors connected in parallel on the right: Worked Example : Drawing circuits I Question: Draw the circuit diagram for a circuit which has the following components: 1 battery 1 lightbulb connected in series 2 resistors connected in parallel Answer Step 1 : Identify the components and their symbols and draw according to the instructions: Worked Example : Drawing circuits II Question: Draw the circuit diagram for a circuit which has the following components: 3 batteries in series 1 lightbulb connected in parallel with 1 resistor a switch in series Answer Step 1 : Identify the symbol for each component and draw according to the instructions: Xem thêm: Physics 10.IX Electric Circuits High School Students Studying the Sciences Physics