Resistivity of a wire - AS coursework

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Homework Help Overview

The discussion revolves around an experiment related to measuring the resistivity of a wire, with participants exploring the appropriate methods and equipment needed for accurate readings of voltage and current.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the necessity of measuring both voltage and current to determine resistance, and question the use of an ammeter for voltage measurement. There is also exploration of using an ammeter in conjunction with a resistor to measure voltage.

Discussion Status

Some participants have provided clarifications on the equipment needed for the experiment, while others have shared insights on the relationship between current, voltage, and resistance. The original poster has indicated that the practical has concluded successfully, suggesting that some guidance was helpful.

Contextual Notes

The original poster mentioned uncertainty about the readings to take before the experiment, indicating a lack of clarity on the experimental setup and 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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