Electric Circuits SNC1P1 Findlay

What do we already know? As we just learned, electric circuits provide a path for electrons to move. Now, it is important to remember that a conductor, such as copper, is FULL of electrons all the time. So as soon as power is given to a circuit electrons will start to move. This is different than a water hose where you have to wait for water to come out of the hose sometimes. ELECTRICITY IS INSTANTANEOUS.

From Yesterday’s Lesson... Yesterday you all had time to build your own electric circuit by using some pretty simple parts: A light bulb, battery and a wire. You might have found that it was time consuming to draw an actual picture of this circuit and its parts, so today we will be learning the proper way to draw electrical circuits. We will call these CIRCUIT DIAGRAMS

Circuit Diagram What is a circuit diagram? Symbols are used to represent different components of a circuit. A picture drawn using these symbols to represent an actual circuit is called a circuit diagram. Next, we will look at the different symbols that are to be used when drawing a circuit diagram.

Circuit Symbols: Battery The most important symbol in a circuit is the battery/batteries, because this is the component of a circuit that keeps the electricity moving. In a circuit, we will call the battery the SOURCE. And they are drawn as follows: Always remember straight lines. USE A RULER. And make sure you remember to put the positive and negative end of the battery on the drawing. The big line is the positive and the small line is the negative. One Battery Two Batteries

Circuit Symbols: Wire Possibly the easiest symbol to draw. But don't forget to use a ruler! Conducting Wire:

Circuit Symbols: Light Bulb A load is any electrical device that converts electrical energy into some sort of usable energy. This could be a motor, a hair dryer, a radio or even a fridge! We can represent the light bulb in one of two ways. The first way is a more general symbol that can represent a variety of electrical appliances (load)... General Symbol (load): Light Bulb Symbol:

Circuit Symbols: Switches A switch is a part of a circuit which either opens (turns off) or closes (turns on) a circuit. When it is open electrons cannot flow and when it is closed electrons can flow. Closed Switch: Open Switch:

How to draw circuit diagrams... When we are drawing circuit diagrams we want to use a few easy to follow rules that will always get us the correct answer: Always USE A RULER! Start with the battery on the left side of the drawing. Make sure you check the number of batteries and that you have the positive and negative sides labelled. From the battery draw a line and then a right angle to the right, draw your next symbol here, it could be a switch or a light bulb... Continue drawing all the symbols and try to spread them out throughout the diagram.

Try This One: Draw a circuit containing 3 batteries connected to each other, a switch so that electricity can flow through it and three light bulbs.