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When trying to determine the ohmic resistance from measurements of current $I(U)$ at different voltages $U$ of a circuit with the ohmic resistance built in, which of the following methods evaluate the data more "accurate"?:

When a regression line is plotted with the form $y=mx$ approaching the ohmic law $I(U)=\frac{1}{R} U$ you can read out the slope $m$ and take its inverse to get the ohmic resistance $R$. At the same time you could get $R$ by taking the quotient of each individual voltage $U$ meassured and its corresponding $I(U)$ and then calculate the average.

Both ways make sense plausibly but which one is more accurate from a mathematical standpoint? And how do you determine the error $R$ in both cases?

shar
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1 Answers1

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Up to a point the question posed in this post is answered in the post Least squares fit versus averaging however there is a little more which might be considered.

If drawn, a trend line would relatively easily help produce some more information, such as:
Are there any anomalous data points?
Is the relationship really linear and if not, over which region is there a divergence?
Do the instruments used have a zero errors as might be shown by the best-fit line not going through the origin.

Farcher
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