Resistivity of a wire - AS coursework

AI Thread Summary
The discussion centers on conducting an experiment to measure the resistivity of a wire using a 100mA ammeter. Participants clarify that to measure resistance, both voltage and current must be recorded simultaneously, necessitating two meters. It is noted that an ammeter can function as a voltmeter when paired with a large resistor, although this may affect measurement accuracy. The original poster successfully completed the experiment, measuring current and voltage, and plans to calculate the wire's resistivity. Overall, the conversation emphasizes the importance of proper measurement techniques in physics experiments.
r0manticide17
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Im to do an experiment tomorrow, but I've no idea what kind of readings to take! I am going to be using a 100mA ammeter, to measure voltage and current. The current is to stay constant more or less but I am not sure what ranges of readings I am to take. Anyone help me please? :cry:
 
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To be clear, will you be using the Ammeter to measure the voltage?

And, is the point of the experiment to measure resistivity, not resistance?
 
To measure the resistance of something, you need to simultaneously measure the voltage across it and the current through it. You will need two meters for this. Are you going to buddy up in the lab?
 
berkeman said:
To measure the resistance of something, you need to simultaneously measure the voltage across it and the current through it. You will need two meters for this. Are you going to buddy up in the lab?
An ammeter can be used as a voltmeter if used in conjunction with a resistor of known resistance (preferably large resisitance).
 
Chi Meson said:
An ammeter can be used as a voltmeter if used in conjunction with a resistor of known resistance (preferably large resisitance).
I know how to use a voltmeter and a resistor together as an ammeter, but I never thought about using an ammeter and resistor as a voltmeter. How does that work? Oh, I get it -- but the resistance of the ammeter degrades the accuracy of the measurement. I guess that's why you said to use a large value of external resistor...
 
thanks for all your replies, but the practical is now over with. Managed just fine, measured current and voltage, worked out resistance, and will be working out the resistivity of the wire soon enough
 

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