Today we are going to show you electrical resistance in action. This is a neat demonstrator for science class. All it is going to cost you is a 9-volt battery and a few incandescent light bulbs and sockets. The wires and clips should be lying around in science lab. Ask the teacher to help you find them, and watch over you as you do this electrical resistance experiment.
The Electrical Resistance in the Demonstrator Experiment
Electrical resistance is the relative difficulty of sending an electrical current through a conductor. Various factors affect this; in fact some materials (wood, plastic, ceramics) do not conduct electricity at all. Shape also has an effect. For example, a thick copper wire has less resistance than a thin one. Hence, it lets more electricity through.
Conversely, a long wire is more resistant than a short one. We can measure the specific resistance of an object using a multi meter set to read ohms, or units of resistance. We can also gauge electrical resistance approximately by noting how brightly a light bulb glows.
The Relationship Between Electrical Resistance and Heat
Resistant materials impede, or prevent the flow of electric current. When some electricity does get through, it generates heat. This heat in turn increases the resistance. In thermal runaway, the heat rises to the point where it may destroy the resistor. Hence, it is important that resistors, conductors, and light bulbs are fit for purpose. Now let us interpret the video.
The resistance of metals increases as they become warmer. This explains why the small light bulb glows brighter when the instructor blows on the large filament to cool it. Why is this important? It is important because temperature affects the behavior of wires, resistors, and other components in circuits. This is why laptops have ventilation slots, and desktops have cooling fans to keep electrical resistance down.
Related
Resistors as the Application of Ohm’s Law
How to Use a Multi Meter to Measure Electricity
Preview Image: Incandescent Light Bulb
Video Share Link: https://youtu.be/teHFi47qCEA
