How does the type of metal affect how much current a circuit has?

Background Research Summary 1.Resistance of various metals: silver 1.6, copper: 1.7, aluminum: 2.7, zinc: According to Ohm’s Law, if the resistance is greater, the current flow will be less. 3.A piece of zinc should create more resistance in a circuit than a piece of silver, copper or aluminum. 4.Silver and copper wires have low resistance so those metals should allow electricity to flow easily through a circuit. 5.A multimeter can be used to measure the amount of current in an electrical circuit.

Research Sources Sources of information on electrical resistance of metals: 1. "How Voltage, Current, and Resistance Relate." All About Circuits Forum RSS. N.p., n.d. Web. 01 Oct "Resistivities for Common Metals." Resistivities for Common Metals. N.p., n.d. Web. 01 Oct "TIBTECH Innovations." Conductive Materials or Metal Conductivity. N.p., n.d. Web. 01 Oct "How to Use a Multimeter." - Learn.SFE. N.p., n.d. Web. 01 Oct. 2013

Hypothesis If the type of metal is zinc, then the current will be lower than if it is silver, copper, or aluminum. The research I found said that silver, copper, and aluminum are better conductors of electricity than zinc. Current should be greater if the metal is a better conductor.

Experimental Set-Up

Variables Independent: type of metal Dependent: amount of current flowing through circuit (amps) Controlled variables: same circuit, same voltage of battery, same multimeter, same size of metal piece.

Materials Piece of zinc, copper, aluminum and silver. Alligator clips to connect parts of circuit 1.5 volt D batteries Multimeter

Procedure 1.Set multimeter to measure current. 2.Construct electrical circuit with D battery, 4 alligator clips, and multimeter. 3.Measure current flowing through circuit and record. 4.Place piece of zinc between two of the alligator clips. 5.Record current flowing through circuit. 6.Repeat steps 4 & 5 two times. 7.Repeat steps 4 – 6 with other types of metal.

Data Type of MetalCurrent (amps) Trial 1Trial 2Trial 3Average Zinc Aluminum Silver Copper Type of Metal vs. Current Produced

Observations Multimeter readings fluctuated a bit - wrote down number that showed up most often. Put a bulb in the circuit to see affect that different metals had on brightness. Brightness of bulb related to how much current flow there was. Could calculate resistance of each metal using Ohm’s Law, and values for current and voltage. Had to replace battery a couple of times to keep voltage at same level for all trials.

Graph

Conclusion Based on my data, I can conclude that the type of metal that produced the greatest current was silver, and the type of metal that produced the lowest current was zinc. The average amperage reading for silver was 0.24 amps and the average for zinc was 0.06 amps. The averages for copper and aluminum fell in the middle range with an average of 0.12 amps for aluminum and 0.18 amps for copper.

Conclusion (continued) The results of my experiment support my hypothesis. Zinc was the metal with the lowest current flow. I was surprised to see that aluminum was the next lowest reading. I had thought that it would have a higher reading than the copper. The results are also in agreement with the research I read on resistance. That information said that zinc would have the greatest resistance, which would result in the lowest current flow.

Possible Sources of Error In conducting my research, I realized there were some aspects of my set-up that may have had an effect on the results. The pieces of metal I used were not all the same length and I know that the length of the metal affects its resistance. Another possible source of error was the voltage of the battery. I checked it frequently throughout the experiment, but it may have varied a little bit from trial to trial which may have affected the results. If I were to conduct the experiment again, I would make sure to use metal pieces that were all the same size and to have a large enough supply of batteries so that the same battery was not used twice.

Ideas for Further Research After conducting the experiment, some other questions came to mind that I might want to research in the future. I would be interested to see if or how much the length of the metal affects current flow. I could have several pieces of the same metal that were different sizes. I would also be interested to find out how other metals, such as gold and tin, compare to the metals I studied in the experiment.