Ohm's Law vs Ohmmeter: Comparing Resistance Values

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Discussion Overview

The discussion revolves around the comparison of resistance values measured by an ohmmeter and those calculated using Ohm's Law. Participants explore the reliability and accuracy of both methods in measuring resistance, considering various factors that may influence the results.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that measured values should agree with theoretical values within measurement errors.
  • One participant notes that the accuracy of measurements can depend on the type of resistor, mentioning tolerances such as 5%, 1%, or 0.5%.
  • Another participant emphasizes that to determine actual circuit values, measurements must be taken due to numerous variables affecting Ohm's Law calculations.
  • It is mentioned that both measurements and Ohm's Law should be used together rather than viewed as separate methods.
  • One participant questions the reliability of each method, seeking a general answer about which is more reliable without specifying particular instruments or resistors.
  • Another participant argues that both methods involve similar components and questions which method is more accurate.

Areas of Agreement / Disagreement

Participants express differing views on the reliability and accuracy of resistance measurements from ohmmeters versus those derived from Ohm's Law. No consensus is reached on which method is more reliable.

Contextual Notes

Participants acknowledge that measurement errors and the specific characteristics of resistors can affect the outcomes, but these factors remain unresolved in the discussion.

surfer
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Are the resistance values of resistors which measured by ohmmeter and Ohm's law equal each other. Which of them are realiby than other? Please help me!
 
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Measured values should agree with theory up to the measurement errors.
 
surfer said:
Are the resistance values of resistors which measured by ohmmeter and Ohm's law equal each other. Which of them are realiby than other? Please help me!

How does your ohmmeter determine a value of the resistance? How does an ohmmeter work?
 
It must be the same within the measurement errors except for the fact that you measure at the boundary values. I mean if your ohmmeter has the measuring range from 1ohm to 10megaohm and you measure a resistor of about 1 ohm or appr.10 Mohm.
It also depends on what kind of resistors you have. Some kinds of resistors have higher accuracy than others. There are resistors with 5%, 1% or 0.5% tolerance etc.
 
In fact, I asked this question in general. So i have wanted you to give a general answer to me. There is no specific ohmmeter and there is no specific resistor. I asked only which one is more reliable? And thank all of you for your interests.
 
I would not consider one more "reliable" then the other.

If you want to know what the actual circuit values are you must measure them, there are to many variables to rely solely on Ohm's law calculations.

For the standard resistor, use the color code to find it's resistance. Now with a voltage measurement and Ohm's law you can determine the current. It is usually difficult to directly measure current since you must insert the ammeter into the circuit.

Thus measurements and Ohm's law must be used together. They should not be seen as separate approaches.
 
They are the same thing surfer. You have to measure volts to come up with a voltage to plug into the formula for ohms law. You have to measure the current also. An ohmeter uses all of the same components that voltmeters and current meters use. So you tell me, which is more accurate?
 
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