Understanding the Ohm: Definition, Explanation, and Examples

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Discussion Overview

The discussion centers around the definition and understanding of the ohm as a unit of electrical resistance. Participants explore the implications of the definition, its interpretation, and related concepts in the context of electrical circuits.

Discussion Character

  • Conceptual clarification
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant expresses confusion regarding the definition of an ohm, suggesting it should describe how much current is prevented rather than how much is produced.
  • Another participant explains the concept of voltage using an analogy of potential energy, relating it to the flow of charge and resistance.
  • A participant attempts to clarify the relationship between ohms, volts, and amps, suggesting that higher resistance corresponds to less current allowed through.
  • Further clarification is provided that resistance is defined as the ratio of voltage to current, with examples illustrating this relationship.
  • One participant acknowledges understanding the concept after the explanations, affirming that lower ohms indicate lower resistance.
  • A link to an external resource on the topic of ohms is shared for additional reference.

Areas of Agreement / Disagreement

Participants exhibit some agreement on the relationship between voltage, current, and resistance, but there remains confusion and differing interpretations regarding the definition of an ohm and how it should be understood.

Contextual Notes

Some assumptions about the definitions of voltage and current are not explicitly stated, and there are unresolved nuances in the interpretation of resistance and its implications in practical scenarios.

Femme_physics
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The ohm is defined as a resistance between two points of a conductor when a constant potential difference of 1 volt, applied to these points, produces in the conductor a current of 1 ampere, the conductor not being the seat of any electromotive force.

I'm not sure I understand this definition, it's written in a rather confusing manner...instead of saying how much ampere is being stopped from flowing, it tells us how much current is being produced!

That's a little confusing...I thought the definition for the resistance SI unit would be how much of the current is prevented...as in a negative number, maybe.
 
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Well, a volt is a POTENTIAL energy. Like say there is a rock on top of a cliff. It has a potential energy, if it were pushed off the edge the potential energy would be converted into kinetic energy.

So, the volt is like a store of charge at one side of a material that wants to go to the side with less charge. (i.e. the rock falling off the cliff to get to a lower energy). If the material slows the charge to move at 1 amp = (1couloumb/sec). The materials resistance will be 1 ohm.

So if the material slowed the charges trying to get to the other side to .1 amps. The materials resistance would be higher... ( 1/.1 = 10 ohms).
 
So let me see if I get it right:

1 ohm is 1 amp being stopped per volt, whereas 2 ohm is 2 amp being stopped per volt?...etc etc
 
not being stopped. being allowed through the material. if 1 amp is being allowed through with a 1 volt potential difference. the resistance is 1 ohm. if 2 amps are being allowed through with a potential difference of 1 volt. The resistance is 1volt/2amps. = 1/2 ohm.

The units for OHM = VOLT/AMP
 
Ah, makes complete sense...so the lower the ohm the lower the resistance right? right. I see now :) thanks.
 
If you are interested in the http://hyperphysics.phy-astr.gsu.edu/hbase/electric/ohmmic.html" ,

micohm.gif


check this out.
 

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