To investigate the resistance of the 3 different types of wires, constantan, copper and nichrome, by using 1 set of circuit. Research: Constantan A metal alloy made of 45 percent Nickel and 55 percent Copper. Constantan wire is used chiefly in electrical instruments and other equipment, which can take advantage of its unusual physical property, which is that, even over wide variations in operating temperature, its electrical resistance stays at an almost constant value. The melting point is 1221 to 1300 i?? C. Has low conductivity.
Wire commonly made from copper by drawing from a hot-rolled rod without annealing; however, the smaller sizes may involve intermediate anneals. Melting point is 1084. 62 i?? C. Has high conductivity. Nichrome A nickel-chromium alloys with high electrical resistance and an ability to withstand high temperatures; used for resistance heating elements. The melting point is 1400i?? C. Has low conductivity. Hypothesis: I predict the copper wire has the lowest resistance. It is because as copper has higher conductivity, the current go through more smoothly so that there are less resisting occurs.
Variable: Independent- Types of wire Dependent- Resistance Control variable Variable How Why Length Keep every wires in same length Because resistance change in length Diameter Keep every wires in same diameter Because resistance change in diameter Voltage (power supply) Keep every power supply at same voltage Because when the strength changes the resistance also change Temperature Take experiment in same temperature condition Because these affect to wires and changes the original resistance Material used in Circuit Use all the same materials.
Because condition will be changed and changes the data Materials: Diagrams: Power pack Constantan wire Copper wire Nichrome wire Standard wire Crocodile clip Ammeter Voltmeter Precaution: – Ensure no water around because they are conductor and charges electricity – Be careful with wire getting burned due to high voltages – Be careful with wire heating up – Watch out on sparks occurred when using crocodile clip Method: 1) Connect up a series circuit 2) Attach an ammeter with a gap between two wire with crocodile clip 3) Attach wires in the circuit 4) Connect voltmeter in parallel to wires.
5) Let the current go through 6) Read the ammeter reading and voltmeter reading 7) Replace the wire, in the same length 8) Repeat Result: Wire TYPE Ammeter reading (A) Voltmeter reading (V) Resistance (V/A) Trial 1 Trial 2 Average Trial 1 Trial 2 Average Constantan Copper Nichrome Conclusion: We can say that each types of wire have different resistance. Also as they can conduct current stronger and conduct power weaker, they will have less resistance.
The result looks good because also in the theory, copper has the lowest resistance and nichrome has higher resistance due to their conductivity. Evaluation: My hypothesis was “I predict the copper wire has the lowest resistance. It is because as copper has higher conductivity, the current go through more smoothly so that there are less resisting occurs. ” This was right because result table shows that copper has the lowest resistance and nichrome has higher resistance. Our experiment is reliable as we had controlled variable well, for example we used everything the same and length that cut off were very accurate.
Improvement that we can do for next time is organizing, because it took more than 10 minutes to set up the circuit and start experiment, everything other was fine. Our data is reliable because we had 2 trials to ensure our results. No anomalous data were occurred in our experiment. However, it could have be occurred by setting the circuit wrongly for example connecting ammeter/voltmeter in parallel/ series or connecting negative and positive opposite. This topic is all related to environments because the wire we used are from natural resources and we were investigating resistance of them.