I was measuring the electrical conductivity of certain wires at school in a lab in Amperes with an Avometer set on ''B'' and the results got:nichrome 0.2mm 1 Anichrome 0.4mm 0.8 ACopper 0.2mm 0.7 AIron 0.5mm 0.23 AAre those results right? And if so does that mean that the Iron wire has the best conductivity among those those indicated?
Conductivity is invese to resistivity. So a high resistance means a low conductivity. High resistance means less current can flow. A low resistance means a high conductivity. Low resistance means more current can flow. Something is wrong with your experiment setup because you don't state the length of the wires. The longer the wire, the greater its resistance. Copper has the lowest resistance of the three types of metals you list. Therefore it should have the highest conductivity and the highest current flow. Yet it has lower current flow than nichrome wire of the same diameter. So I have to assume the 0.2 mm copper wire was considerably longer than the 0.2 mm nichrome wire. Please check this out and ask the question again when you find out the lengths of the various wires you tested. The other thing I would want to know is what kind of power supply you were using. Was it a constant voltage supply ? What other devices were in the test setup ? Do you have a circuit schematic ? You can post an image on image-sharing websites and put the link in your question.
Perhaps you did not make a good electrical connection at the ends of some of those wires multiple somethings are wrong. For the same length and same voltage applied; copper and iron should have been the most current about one amp 0.4 nichrome a bit less perhaps 0.8 amps. 0.2 nichrome down by 4 times to perhaps 0.2 amps Other possibilities are decreasing readings are due to the battery voltage decreasing or you have wrong labels on your wires or you are reading the Avometer wrong. Does Avometer stand for amp, volt, ohms? Perhaps the B range is ohms and you were applying voltage to the ohmmeter that can give some very strange readings. Neil
conductivity is the inverse of resistivity which is measured in units of s/m which isn't amps. Amp is a measure of current flow through a wire. If you applied the same current through (voltage across) all the wires, than the one that allows the most current to pass through is the most conductive. The diameter of the wire plays a big part too, the thicker the wire, the more current can pass through. The thinner the wire, the less current. iron has the largest diameter and the smallest current flowing through it, that tells you that its conductivity is lower than the others, and therefore has a higher resistivity. ALSO, the Ni-chrome with the smaller diameter is showing a higher current value than the Ni-chrome with the larger diameter. The conductivity for the material itself is a constant, so the fact that the smaller diameter one has a larger current value going through it has nothing to do at all with the conductivity of the material, but how much current you chose to pass through the wire during the experiment. You must not have had a constant current or voltage across it at the time of the measurement. In general, the copper wire is the most electrically conductive.
Those are not conductivities, those are just currents in a wire at some voltage. Are they right? I'd need the voltage and the length. You have to calculate the conductivity. Here is the formula below. Calculate the resistance as R E/I. Calculate the cross-sectional area of the wire in m? from this A πr?, r is radius of wire in m Resistance of a wire in Ω R ρL/A ρ is resistivity of the material in Ω-m L is length in meters A is cross-sectional area in m? Then ρ RA/L conductivity is 1 / resistivity or conductivity L / RA
No idea what the B range is on an AVO and I've used a few. The fact that twice the diameter of nichrome wire passes less current sounds like there is something not quite right with your experimental method, and no Iron passes the least current (assuming that's what you are measuring). so it doesn't have the best conductivity.
