Resistivity of a wire - AS coursework

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SUMMARY

The discussion focuses 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 measured simultaneously, necessitating two meters. An ammeter can be adapted to function as a voltmeter when paired with a large resistor, although this may affect measurement accuracy. The original poster successfully completed the practical, measuring current and voltage to calculate resistance and is now preparing to determine the wire's resistivity.

PREREQUISITES
  • Understanding of basic electrical concepts, including voltage, current, and resistance.
  • Familiarity with using an ammeter and voltmeter in experimental setups.
  • Knowledge of Ohm's Law and its application in calculating resistance.
  • Experience with laboratory equipment and safety protocols.
NEXT STEPS
  • Research the principles of resistivity and its calculation in different materials.
  • Learn about the proper use of ammeters and voltmeters in electrical measurements.
  • Explore the effects of resistor values on measurement accuracy in circuits.
  • Investigate common laboratory practices for conducting electrical experiments.
USEFUL FOR

This discussion is beneficial for physics students, educators conducting laboratory experiments, and anyone interested in understanding the principles of electrical resistance and resistivity measurement techniques.

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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