Introduction: Resistance is how difficult it is for electricity to pass through an electric circuit. Because the electrons pass through against the current the longer the wire the more the resistance, but the wider the wire the more room the electrons have too pass through so it is easier. The electrons, which pass through the circuit, are the free electrons in the metal that the wire is made out of. These free electrons push against the current causing the current to slow which is why we call it resistance.= Electric Current= Wire= ElectronFew electrons so easy to pass throughLots of electrons so harder to pass throughAim: To discover if and how the length of a wire effects the resistance of an electric circuit.
PlanI am going to do an experiment to investigate if the length of a wire effects the resistance of a circuitSafety I will have to a make sure there that I take some safety precautions before I do this experiment like the usual do not sit down while doing the experiment wear safety spectacles and a lab coat make sure the area is clear and there is no water about as we using electricity.Fair test: To make this a fair test I will keep all aspects the same apart from the varying length of wire, although the volts passing through the circuit in the first reading was on two volts and for the last two readings was on four volts. The thickness of the wire the length of the none varying wire which connects the voltmeter ammeter battery and varying length of wire will be the same.Prediction: I predict as the length of the wire increases the more resistance there will be in the circuit because the electrons pushing through the circuit will have more to push through as the wire length increases.Method: Set up the circuit shown in the diagram below.V= Volt meterL= Different lengths of wireA= Amp meterNow change the length of the wire recording the amps and volts in a result table each time in order to work out your resistance.
ResultsWire lengthAmps1(2v)2(4v)3(4V)Amp Avg.Volts123VoltAvg.Resistance50cm0.
823.2012.8ConclusionSo my results prove that the resistance in an electrical circuit dose increase as the length of a wire dose. In my results as you go down the table with the increasing lengths of wire the resistance goes up with it all apart from the last result. Which was an incorrect set-up of the circuit.EvaluationThe results were not as accurate as they could have been because of the flickering ammeter and voltmeter which could have altered the average reading which is what my graph is plotted on. The length of wire may have been measure imperfectly and the sallotape that held the wire down restricted the maximum length.
There could also have been kinks in the wire affecting the measurement or short circuiting the wire however on the whole my experiment showed that resistance increases as the length of a wire increases.