Circuit With Resistors In Series example essay topic

Investigation of four resistors connected in series and in parallel. Background: Resistance is what opposes the flow of electrons in an electric current through a conductor. Resistors are conductors that have a high resistance. A conductor is the material through which an electrical current flows. The Resistance, (R) of any conductor is given by the equation = V / I where V = p. d. across the conductor I = current according to Ohms Law V = I / Rain: The aim of this experiment is to investigate how different amounts of resistors in series and in parallel affects the resistance of an electrical circuit, and what effects they have on the current. Variables: number of resistors series / parallel Constants: voltage length / materials of wires type / resistance of resistors I will use a voltage of five volts in each experiment.

I have chosen this voltage so that the circuit does not heat up too much. Method: I will have to set up circuits as in the diagrams below to start with, both the parallel and series circuits, and then, with the voltage set to 5 volts, measure the current in each circuit with different amounts of resistors. Having taken each result, I will turn off the power supply, so that the resistors do not get too hot, because this would change their resistance. I will take measurements of the current at 5 volts, with 1 to 4 resistors in parallel and in series.

To ensure that my results are accurate, I will repeat each reading, and use the average result. For safety, I will make sure that I do not touch any of the resistors, because they may be hot enough to burn. Apparatus: Voltmeter Ammeter 4 Identical Resistors Power Supply Insulated Wires Diagram: Predictions: I am expecting that with the circuit with resistors in series, as I add resistor of a certain resistance, then the overall resistance will increase by that amount. This is because resistors in series add together, because the current must go through one resistor, then the other, losing more power each time. Therefore I predict that as the number of resistors doubles, then the total resistance will double.

With the circuit with resistors in parallel, I am expecting that as I double the amount of resistors, then the total resistance will halve, because the current has more material to go through. This concept is similar to that in the experiment in which you look at how the thickness and the length of a wire affects the resistance. Using a long wire is like having resistors in series because the current has to flow through more material with resistance in it, so there is more total resistance. Using a thick wire is like using several resistors in parallel because the current has a wider route to flow through, so it should be able to flow through with more ease, so the total resistance will be less. Analysis: Looking at the graph, you can see that with a circuit with resistors in parallel, the more resistors there are, the less the total resistance is, and with the circuit with resistors in series, the more resistors there are, the higher the total resistance. This ties in with my prediction that more resistors in series means a higher resistance, and more resistors in parallel means a lower resistance.

The graph for resistance against number of resistors in parallel shows us that the resistance is inversely proportional to the number of resistors in parallel. Ohms Law tells us that R = V / I which means that resistance is inversely proportional to the current, so this means that the amount of resistors in parallel is proportional to the amount of current that is getting through. The graph for resistance against the number of resistors in series, is directly proportional, which means that if you were to double the amount of resistors in series, then the total resistance would double, which proves the idea that current going through consecutive resistors loses power in one, and then loses the same amount of power in the next resistor. This power, or energy, is being converted into heat energy in the resistor.

I think that the result from the circuit with four resistors in parallel is an anomalous result, because the other three are all in a straight line, directly proportional to the resistance. Instead of using the average, it would be more sensible to use the result of 45.73 with four resistors in series, and disregard the result of 49.80.