Confusion with regards to power lines and the power lost

AI Thread Summary
Power loss in transmission lines is calculated using P=I²R, where increasing voltage reduces current and thus decreases power loss. The confusion arises from the relationship between voltage and power loss; while P=V²/R suggests higher voltage could increase power loss, this only applies to the load, not the transmission lines. The relevant voltage for calculating power loss is across the transmission cables, not the load. It's important to distinguish between ohmic and non-ohmic conductors, as this affects the validity of the calculations. Understanding these concepts clarifies how power is dissipated in transmission systems.
Coolamebe
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Ok, so the title was pretty vague, I'm not sure how to succinctly describe the confusion. Anyway, so I've learned that the power lost is P=I2R, and so by increasing the voltage, as P=VI and is constant, the current will be lowered, and thus the power lost will decrease.
I'm confused about a couple things. While my physics teacher was specifically talking about P=I2R, should not P=V2/R also give the value, and so by increasing the voltage we increase the power lost? Is this not a contradiction?
I feel like it could be remedied if the wires in power lines are not ohmic conductors and so half the math I did above is invalid.
Anyway, any help would be greatly appreciated, thank you!
 
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The calculation relates to the power dissipated (lost) in the transmission cables so the voltage you need is the voltage across the cables. I think you are confusing this with the voltage across the load (at the end of the cables)
 
lychette said:
The calculation relates to the power dissipated (lost) in the transmission cables so the voltage you need is the voltage across the cables. I think you are confusing this with the voltage across the load (at the end of the cables)
Can you explain this a little more in depth? My teacher explained this very superficially so I'm not too sure on this.
 

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