Electrical Circuits

Uma loves to do experiments... so her friends surprised her with an experiment kit where she has to build... Electrical Circuits Before Uma starts, she reads the instructions because she knows electricity can be dangerous! And the same applies to you at home: electricity is very dangerous. Experiments with electricity can only be done with kits like Uma's. If you want to do something with electricity, always ask your parents first! In Uma's experiment kit, there are two pieces of wire... with crocodile clips on each end... the light bulb ... and a battery. She wants to try to light up the lightbulb. First, Uma looks at the battery. The battery has a postive terminal with a PLUS symbol... and a negative terminal with a MINUS symbol. If Uma clamps one of the wires to the positive terminal pole... and the other end... goes to the lightbulb... what do you think will happen next? (...) Absolutely nothing! How unusual... what would Uma have to change to make the lamp light up? (...) Uma should take the second wire and clamp it to the negative terminal pole. Where should the other end of the wire go? (...) Uma can attach it to the other connection of the light bulb! Do you think the lamp will shine this time? (...) Indeed! But why? Uma built an electrical circuit, which is a complete path around which electricity can flow. We can also draw it! First, represent the lightbulb, using a circle with an in it. Next, the wires are represented using straight lines. Last, the battery is represented with two lines that are different lengths. The longer line represents the postive terminal and the shorter line represents the negative terminal. Let's draw the electrical circuit Uma built. First, draw the battery, the source of the electricity. Next, draw the lightbulb. Then connect the POSITIVE terminal pole of the battery to the light bulb with a wire. The wire is a conductor, or a material that allows an electric current to pass through easily. Would this be enough to light up the lamp? (...) No, the lamp needs the second wire from the light bulb to the NEGATIVE terminal pole... because the current needs to flow from one pole to the other. The current travels through the wire... through the lamp... and through the second wire to its destination in the other pole. On its way, the current lights up the lamp. Since the current can only FLOW in a circle, we call it an electrical circuit. In order for this to work, the circuit must be CLOSED, meaning everything must be connected by wire. While Uma looks for her cell phone to send a picture to her friends, let's summarize! Remember, an electrical circuit is a complete path around which electricity can flow. Current flows from the positive terminal pole to the negative terminal pole. We can easily draw a circuit using special symbols for the battery... the conductive wire... and the light bulb. But, be careful! Electricity is very dangerous, always ask your parents first before you do anything with electricity. Uma is about to take the perfect picture...Oh no! Good thing there is electricity!