Teaching notes 1 Use fine gauge wires. Apparatus and materials Cells, 1. Discussion Overall, my results are very consistent with my predictions.
Variables There are different variables that can be changed in this experiment; these are the independent variable. Selection of reels of Eureka wire also known as Constantan or Contra of different gauges, e.
This Resistance experiment coursework was safety-checked in August However, this would then lose its value as an open investigation. Resistance experiment coursework will repeat this method every 5cm until I get up to cm, taking three readings from both the voltmeter and ammeter each time to ensure accuracy.
Variables Safety I will ensure experimental safety by confirming that all the wires are connected properly and that none of the insulation on the wires is worn. When using a power supply, high currents will cause the safety cut-out on the power packs to automatically switch it off.
However, using new pieces of wire each time would have been too impractical and time-consuming in the context of this lesson. This will reduce the chance of false readings and will cancel out any anomalous results. Note the reading on the ammeter.
I will place one crocodile clip at 0cm on the wire and the other at 5cm to complete the circuit. However, due to my line of enquiry, I will only change the length of the wire. I have taken three reading and have worked out the average, shown in red.
If short lengths of wire are used with relatively high currents and voltages, then significant electrical heating may also occur. Graph Graphing these results shows a nearly straight line, illustrating a strong positive correlation between length and resistance, which is consistent with my prediction.
I will stand up during the investigation to ensure that I do not injure myself if something breaks. This experiment can be used as a more open-ended investigation.
Students should be encouraged to adjust the voltage to keep currents small with every set of readings. This discharges the cell rapidly and can make it explode. I think my method could have been improved to produce results that were even more consistent.
For example, I could use different types of wire instead of using only nichrome. Overall, I think my method was sufficient to obtain reliable results. However, I made sure that the wire remained straight throughout the experiment.
Students will find it easier to measure at a prescribed length if they tape the wire to a metre rule with insulating tape and make connections with flying leads rather than crocodile clips.
I will switch off the power pack, move the crocodile clip that was at 5cm up to 10cm, and switch on the power pack. If too thick a wire is used, the results may be affected by warming of the wires.
Most of the data points were on, or very close to, the line of best fit. The variables I will control will be the type of wire resistivity and the cross-sectional area of the wire.
There are no anomalous results that I would consider to be far away from the line of best fit. This confirms the first part of my prediction: The negative connection is the centre of the base with an annular ring of insulator between it and the can.
Below is a table illustrating the effect of changing the variables see Table 2: I will also ensure that the wire does not heat up too much by confirming that I do not set the voltage too high on the power pack and by maintaining the same the voltage for every reading.
Selection of reels of different wires e. I think that the range of my results was sufficient enough for me to draw a valid conclusion about how the length of the wire affected the resistance.
At each stage they can connect the circuit, take readings quickly and then disconnect the power supply. I will also control, using the power pack, how many volts pass through the wire. I will then turn the power pack on and record what voltmeter and ammeter readings.
In addition, I will make sure I turn the power pack off after each reading.
There are possible sources of error that might have led to inconsistent results, such as a kink in the wire.Class practical A simple investigation of the factors affecting the resistance of a wire.
Class practical A simple investigation of the factors affecting the resistance of a wire. This experiment can be used as a more open-ended investigation. Students can select the variables, the ranges of results and the equipment used. The amount of. Essays-SCIENCE COURSEWORK: RESISTANCE OF WIRE EXPERIMENT.
Risk Assessment To keep the experiment safe I shall keep electrical conductors away from the plug sockets. Factors Affecting the Resistance of a Wire The aim of this experiment is to investigate one factor that affect the resistance of a wire. I will do this by performing an experiment.
Tungsten's resistance increases as the lamp gets hotter, but if it could be maintained at a constant temperature then its resistance would be constant. 4 For suggested graphs. This experiment was safety-checked in January - GCSE Physics Coursework - Resistance of a Wire Coursework Resistance of a Wire Task To investigate how the resistance of a wire is affected by the length of the wire.
Theory What is resistance. - Resistance of a Wire Experiment Task To investigate how the resistance of a wire is affected by the length of the wire. Theory What is resistance. Physics Coursework Objective: My objective in this experiment is to investigate one of the factors that affect the resistance of a piece of wire; the one I am investing is the length at constant temperature.Download